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Gwynedd
November 15th, 2008, 10:31
Hi, guys. I haven't been around for a while. I had a long drawn-out divorce and some health issues, but I finally was able to set up my MacBook Pro to play CFS1 and FS2004. I see some familiar faces, but all my old posts have been deleted :( What happened?
Are the old JG-57 guys still here as well?
Just checking in. Good to see you again.
Gwen

humbles
November 15th, 2008, 10:37
WB ~S~Gwynedd

smilo
November 15th, 2008, 11:07
hello Gwynedd,
welcome home.
all posts were lost a short while back due to a site hack job and a crash. pity, there was some good stuff that was lost.
so it goes.
as with life in general, people come and go.
the JG57 bunch broke for IL2 and haven't been seen since.
some are gluttons for punishment and stick around.
sorry about your divorce, unless it is for the better
and I hope your health issues are resolved

is Patty Wagstaff related to Jeremy Wagstaff, technical commentator on BBC/NPR?

Gwynedd
November 15th, 2008, 12:22
hello Gwynedd,
is Patty Wagstaff related to Jeremy Wagstaff, technical commentator on BBC/NPR?

Thanks for the warm welcome. The divorce was definitely a good thing. The marriage was entering a dangerous turn for me personally and I'm safer single. The health issues followed from that and having to adjust medication dosages. I hope that will be okay.
It's a real shame some of the old crew left, and a bigger shame that so much of our old history here was lost. Cyber vandalism is still vandalism.
No, Patty Wagstaff is the most famous female pilot in the world, I think. Many consider her the greatest stunt pilot - male or female - in the world. Here is her website: http://www.pattywagstaff.com/

smilo
November 15th, 2008, 12:37
thanks for the link, it looks interesting.
I will check it out at a calmer time.
the Jeremy/Patty relation question was a bit of a joke.
admittedly, not a very good one.

Johnny
November 15th, 2008, 12:53
~S~ Gwynedd,

"Patty Wagstaff is the most famous female pilot in the world, I think."

I thought it was my great-grand aunt Katherine Stinson. But that was then and most planes had two sets of wings. http://www.sanantonio.gov/aviation/stinson_history.asp

Welcome back.

J.:isadizzy:

Darn you P&W, Sweet home Alabama, Lord I'm coming home to you....and the Governor too...

Gwynedd
November 15th, 2008, 14:44
I didn't know that about your family history. You should be proud. I agree that Katherine was a great aviator. I also did not mean Patty is the greatest in history. That would also exclude Amelia Earhart, Amy Johnson, Bessie Coleman and others. And God only knows how many anonymous Russian women died fighting the Luftwaffe. The Soviets only issued parachutes to men! :angryfir:



~S~ Gwynedd,

I thought it was my great-grand aunt Katherine Stinson. But that was then and most planes had two sets of wings. http://www.sanantonio.gov/aviation/stinson_history.asp

Welcome back.

J.:isadizzy:

Darn you P&W, Sweet home Alabama, Lord I'm coming home to you....and the Governor too...

smilo
November 15th, 2008, 15:38
I am surprised that Johnny didn't invite you to come kick some virtual male butt tomorrow.
all you really need is CFS with stock aircraft,
the CFO_weather.dll dropped into the Combat Flight Simulator Modules folder,
the line in the COMBATFS.cfg COLLISION_SEC=1 needs to be changed with Notepad to COLLISION_SEC=-1
a headset and mic comes in real handy so we can talk and of course, you need to install TeamSpeak Client2.
I realise that this is a lot to get done in a few hours, but there's always next week if it's too short notice.
we would love to have you along, if you're up for it.
let us know if you need assistance getting set up
we meet Sundays at 15:00 GMT
TeamSpeak IP is 24.102.61.2:8890
password=****
the Game IP=is posted on TS window.
GAME IS UP NOW!!!

Ivan
November 15th, 2008, 16:06
Hello Gwynedd,

I do not believe you are correct regarding Russians issuing parachutes only to male pilots. There is quite a lot of contradictory photographic evidence. Even female gunners (I remember a rather cute blonde gunner from a Stormovik that was wearing a parachute.)

- Ivan.

Johnny
November 15th, 2008, 17:42
~S~ All,

No parachute for women, the Russians were on target with that one. The women would probably take the silk and make undies. I would not be surprised if the only gave them enough fuel to get to were they were going. The woman you saw Ivan did not have a parachute, that was her purse.

Na! Aircraft was in short supply and I am surprised they gave anyone a parachute. They wanted the aircraft back, hopefully in one piece.

smilo,

I did not tell her because every time we have a female in the game they embarrass the guys by shooting them down. And B_ball will be hitting on her the whole time, tying up the team-speak channel.

J.:costumes:

Ivan
November 15th, 2008, 18:09
Hello Johnny,

I know you are joking, but you should remember that most fighters of that period had real "bucket" seats that needed a cushion (read parachute) in order to be used. Whether you strapped it on was your option though.

- Ivan.

smilo
November 15th, 2008, 18:27
yes, I fondly remember Baby Dragon taking 1100 and the rest of the Allied hot shots to task one Sunday afternoon a few months ago.
Lordy, that was fun stuff.
oh yeah, remember Eyes? that girl was vicious and Lady Sue was no slouch either.

Gwynedd
November 15th, 2008, 19:35
The most vivid account I had in mind was a German ace who had to fight tooth and nail to escape a Russian Yak pursuing him. He finally shot it down behind German lines and returned to the site to find that it had been a woman pilot and she had no parachute, so she died. The German found that brutal. It struck me to the heart that a man serving under Hitler found the Soviets brutal.

Here is a more exact reference about a women's Soviet bomber unit:
"Made predominantly of wood and fabric, the aircraft were fire hazards and many accounts given by crews of the night bomber squadrons related to their fear of catching fire and burning to death. Parachutes were expensive and not available until 1944.'

That account and others can be found at http://www.ctie.monash.edu.au/hargrave/soviet_women_pilots.html



Hello Gwynedd,

I do not believe you are correct regarding Russians issuing parachutes only to male pilots. There is quite a lot of contradictory photographic evidence. Even female gunners (I remember a rather cute blonde gunner from a Stormovik that was wearing a parachute.)

- Ivan.

Gwynedd
November 15th, 2008, 20:24
Oh dearie me!
Okay let's start with the silk statement first. (Sorry, but I teach Polymer and Fiber Engineering; that's my turf) The Japanese and Chinese were the only aviators who had silk parachutes. Silk comes from moth cocoons that can only survive in Asia; Russia, North America and Europe could not get it because of the naval war in the Pacific and Mao's communist army controlling the passage to Siberia. The Soviet Union was not an ally of China until after the US dropped the atomic bombs on Japan.
So...The Germans used rayon made from the trees in Bavaria, Czechoslovakia and Austria. (It comes from pine trees.) The Americans used a novel invention of Dr. Wallace Carothers of DuPont that no one had any idea what to do with until then. It was called Nylon. It comes from petroleum and America had plenty back then. It also found good use as stockings, and men usually are happy about that application. American-made chutes did not burn up if a pilot bailed on fire from his plane. German rayon chutes did burn. They were cellulose and acted like a thin sheet of wood in a fire.

Now, I really appreciate the invitation to fly with you, but I don't think I will have time this weekend or next. I have to prepare a test for a class on Monday and have a long business call tomorrow for a special project. Next week is going to be really busy. My real world research is armor, and we are making prototypes for the V-22. I need to supervise the students doing the assemblies and drag my son out to shoot the samples for me to see which ones work. I also would need time to come up to speed on all those extra applications. But I do want to give it a try.

And guys, does anyone really want to hit on an over the hill engineering professor? We're not known for being sexy unless you get excited about women working differential equations!



~S~ All,

The women would probably take the silk and make undies.
smilo,

I did not tell her because every time we have a female in the game they embarrass the guys by shooting them down. And B_ball will be hitting on her the whole time, tying up the team-speak channel.

J.:costumes:

hubbabubba
November 15th, 2008, 20:55
Hello Gwynedd:wavey:

And welcome back.

BTW- when over the hill, you tend to pick up speed...:kilroy:

Johnny
November 15th, 2008, 23:15
~S~ G,

B-Ball is a young South American Hot Blooded Woman Chaser. Blind, cripple or crazy, knock-kneed, bow-legged or lazy, young, old and everything in between. He can't help it, he was born that way. If I said my name was Jane, he would have to hit on me. I think he is just practicing his lines. He is also a great bomber pilot who will dogfight you in a bomber and win. When he flies upside down, it is time to "Hit the Rip-Stop Nylon." Your toast.

j:costumes:

Ivan
November 16th, 2008, 02:39
Hello Gwynedd,

What will your son be using for the armour test? I hear that the 7 mm Magnum works pretty well for AP use. I'd imagine that just about anything with a reasonably high sectional density bullet at high velocity (.25-06, .22-250, .300 (Just about anybody's) Magnum) should work well.

Regarding Parachutes, It sounds like you are describing a Po-2 biplane for night use. I wonder what folks used as a seat cushion if there wasn't a parachute pack?

- Ivan.

smilo
November 16th, 2008, 05:01
good stuff Gwyn, especially the last line.
take your time, we're patient and don't forget what I said about help getting set up.
it's a snap, really.
BTW, I edited in the TS password above for those who want to join in today.

Gwynedd
November 16th, 2008, 15:12
Hi, Ivan. I just dropped in for a moment to take a breather from test composition and business calls.
We will be using the two primary threats in theater for US rotary aircraft. Those are 7.62 x 39 (both FMJ and AP) and 7.62 x 54R (light AP and AP). I can't say more about the armor itself, but we have to keep in mind that power to weight ratio puts the armor factor in the denominator. Engineering is trade-offs.
You are probably right about the PO-2's, but there are loads of stories on that website about others as well. The Nachthexen were night fighter pilots with no radar. Pretty amazing stuff.
And the other question: Pillows.


Hello Gwynedd,

What will your son be using for the armour test? I hear that the 7 mm Magnum works pretty well for AP use. I'd imagine that just about anything with a reasonably high sectional density bullet at high velocity (.25-06, .22-250, .300 (Just about anybody's) Magnum) should work well.

Regarding Parachutes, It sounds like you are describing a Po-2 biplane for night use. I wonder what folks used as a seat cushion if there wasn't a parachute pack?

- Ivan.

Pratt&Whitney
November 16th, 2008, 16:15
I heard Diff Eq...

Talk nerdy to me :redf:

Engineering is sadly bereft of any large proportion of females...

Sounds like you do some really cool stuff! :ernae:

Ivan
November 16th, 2008, 17:24
Hello Gwynedd,

Believe it or not, I kind of had that same thought right after I sent that last message. We KNOW the high velocity stuff can defeat a substantial amount of armour. Armour for the military doesn't often face a commercial magnum round though. I figured that if you were working with stuff for a tank or armoured car, there doesn't need to be a lot of technology behind it. Just about any reasonable weight of steel will defeat just about anything hand held short of a 14.5 mm Russian or a .50 Browning.

The alternative that I was guessing was add-on armour for a Humvee or Helicopter. I was figuring Humvee because the armour for a helicopter should be an integral / structural component for best efficiency when weight is a factor.

Just as a matter of note, as I see it, the 7.62 x 39 isn't a particularly great threat because from personal observation, they don't penetrate worth anything. I used to collect lead from the berms behind one of our club's ranges after closing. What I found was that I collected LOTS of 7.62 x 39 bullets because unlike most jacketed rifle bullets, they didn't dig themselves very deep into the dirt.

What is really cool for those of you who haven't done this is that after a good rain, you find bullets sitting on top of a little column of dirt because the rain washes away all the dirt that wasn't shielded by a bullet. This doesn't seem to work with anything below about .30 caliber though.

Besides the 7.62 x 39 and 7.62 x 54R, do you also happen to have a 5.45 mm gun? I personally have never owned or fired one of those.

BTW, I believe the Nachthexen were actually night bomber rather than fighter pilots. I can't imagine trying to intercept anything in a Po-2.

Best regards,
- Ivan.

winslow33
November 16th, 2008, 17:48
I can't imagine trying to intercept anything in a Po-2.

Just quickly seeing this and not having time to look at any other posts so excuse me if this is off topic. In researching the Eastern Front for the 67th, I found out that the Po-2 was used for nuisence attacks at night. The pilot would cut the engine, glide in silently, drop the bomb(s), gun the engines, and get the h:censored:ll out of there. It never acheived much damage, but the point was more to disrupt the sleep of soldiers. The Germans had to scramble into the air after such an attack.:isadizzy: So essentially, the russians were bombing all the time when they had the resources. Mild attacks in the morning, Worse ones in the afternoon, the worst in the evening, then Po-2 attacks at night.:isadizzy:

Pratt&Whitney
November 16th, 2008, 18:35
This reminds me of a recent discussion I had about "bulletproof" vests... Someone referring to Flak Jackets as such... Pretty sure they are "bullet resistant"

Having done a fair share of "experimental" shooting at things:
The .50 S&W is a beast, and an absolute blast to fire. But as far as power, it is still lacking to rifles.
30-30's are very efficient at finely distributing cantaloupes.
A .300 will very nearly penetrate a very mild steel plate of ~1".

In the IDE building on campus, there is a 2" thick or so chunk of aluminum that was shot with a plastic BB, albeit at an extremely high velocity. The impact left a bowl shaped crater, complete with a "splash" appearance around the rim, that very nearly penetrated the slab. I used to have a picture on my phone.

I'd say, that there is almost nothing that you can't penetrate, given the right projectile, right power, and enough ammunition. :banghead:

Ivan
November 16th, 2008, 19:19
Hello P&W,

I also have done a fair amount of silhouette shooting with a .300 Winchester Magnum but haven't had the same kinds of results. Then again, we were shooting the 1/2 inch steel targets from 200 meters.

- Ivan.

Pratt&Whitney
November 16th, 2008, 19:37
Hello P&W,

I also have done a fair amount of silhouette shooting with a .300 Winchester Magnum. I'm not quite sure what version of .300 Magnum you are using, but a 1/2 inch thick sheep silhouette was pretty safe from penetration by the match 168 grain HPBTs we were using. It was suspended on ropes and being shot from 200 Meters out, but I don't believe we could blast through it even up close. Now perhaps with AP ammunition, we could have done better? Perhaps the sheep was hardened steel?

- Ivan.

I would venture to guess that your sheep target silhouettes are a reasonably high carbon steel, and is probably quenched and tempered.

The piece of mild steel in question, I really believe was not only a weak alloy, but was also I believe annealed (as in, when it was cut out, it was heated to a temperature > 740*C, returning it to Austenite, and allowed to cool in air. It was a 4"x4"x1" piece, cut out on all 4 sides with an oxyacetylene torch.)

The piece was also pinned down, and backed by a piece of wood, IIRC... Shot from 20-50 feet. I am not sure what was used other than a .300 Magnum, I wasn't there when they shot it. I just saw the effects. They also shot another piece a few times with a .270, but with less dramatic results.

Gwynedd
November 16th, 2008, 20:15
Let me answer both Pratt & Whitney and Ivan here because we're all on the same theme.
First, you are correct that nothing is truly bulletproof. Somebody can make something that can get through whatever armor you create. "Bullet resistant" is a lawyer term to avoid lawsuits from families whose husband, wife, son or daughter was shot while wearing armor that was not designed to stop the bullet that penetrated. Next, FLAK jackets are technically just intended for shrapnel and unless soft body armor is made to MIL SPEC for handguns and submachine guns, it is only for that use.
I have never fired a .50 S+W myself, but I have stopped the bullets from one in 1/5 of the layers of my military soft armor prototype at a range of 15 feet. I also have never fired the Russian 5.45, but I did let the FBI test some of my hard armor against AR-15's with 5.56 mm rounds. That round does not perform well at all in armor if you can destabilize it early, and that is really the design of the 5.56. It has a CG near the tail and tumbles in a target. The 7.62 x 39 is really not a high powered rifle bullet because it only has a muzzle velocity between 2200 - 2400 fps. The .30-30 has similar characteristics. They can actually be more devastating to some ceramic armors than bullets with speeds in the 2700 - 3200 fps ranges.
My task in the V-22 research is to find something to set behind the present carbon fiber composite skin. Carbon fiber is awful in ballistic applications because it is all Young's modulus and no yield at all. Ballistic resistance relies on both high energy to break and low breaking strain. Spider silk has been touted as a good potential ballistic material, but I think I was really the first person to point out to the Army that energy to break alone does not make a good fiber. Spiders kill by tiring our their prey in very resilient, high energy (work) to break, and mediocre modulus web before they poison them. The example I gave one of the women in that command was that if a vest stops a bullet without fiber breakage, but it stops a foot on the other side of the body from the entry direction, you have still killed the soldier. She quoted me in numerous meetings after that. I wish she had referenced me after the quote! :frown: Only a few fiber materials have the properties we can use and they include aramids (Kevlar etc), extended chain polyethylenes (Spectra etc), and poly{2,6-diimidazo[4,5-b4',5'-e]pyridinylene-1,4(2,5-dihydroxy)phenylene}. They call that last one M5, thank God. No fiber based material by itself can stop a rifle bullet more powerful than a .22 LR.
If there is any way to post a PowerPoint somewhere here on this board, I can do that for you guys. Otherwise, maybe a local university library can get you a copy of this book http://www.amazon.com/Military-Textiles-Woodhead-Publishing/dp/1420079603/ref=sr_1_1?ie=UTF8&s=books&qid=1226897632&sr=1-1 I wrote Chapter 2 or one of the early ones in there.
One question for you, P&W. You are only 21, but your avatar has a slide rule. Have you ever used one? It has been a long time, but I think I could pick it back up easily with all the practice we used to get.


This reminds me of a recent discussion I had about "bulletproof" vests... Someone referring to Flak Jackets as such... Pretty sure they are "bullet resistant"

Having done a fair share of "experimental" shooting at things:
The .50 S&W is a beast, and an absolute blast to fire. But as far as power, it is still lacking to rifles.
30-30's are very efficient at finely distributing cantaloupes.
A .300 will very nearly penetrate a very mild steel plate of ~1".

In the IDE building on campus, there is a 2" thick or so chunk of aluminum that was shot with a plastic BB, albeit at an extremely high velocity. The impact left a bowl shaped crater, complete with a "splash" appearance around the rim, that very nearly penetrated the slab. I used to have a picture on my phone.

I'd say, that there is almost nothing that you can't penetrate, given the right projectile, right power, and enough ammunition. :banghead:

Pratt&Whitney
November 16th, 2008, 20:39
The .30-30 has similar characteristics. They can actually be more devastating to some ceramic armors than bullets with speeds in the 2700 - 3200 fps ranges.

One question for you, P&W. You are only 21, but your avatar has a slide rule. Have you ever used one? It has been a long time, but I think I could pick it back up easily with all the practice we used to get.

Thank you for taking so much effort to reply to Ivan and myself :applause: A lot of interesting info

I tend to drag my professors into discussions like this... :redf:

I tend to think of the 30-30 as a bludgeoning round, something almost more akin to a shotgun slug, in that it has a rounded/flat tip, and almost all the rounds I have encountered are lead nosed and are designed to expand quickly. So when the hit something that can give them enough resistance to bloom into a mushroom, they can deliver a nice chunk of energy to them. Not great for penetrating through a fiber-based like a ballistic tip might, but I could see why it might be devastating to a ceramic plate if it struck perpendicularly. From what I remember the CoM would be near the center or slightly rearward.

I am 21, and that picture is actually of Joe Miner, our mascot. Formerly the University of Missouri-Rolla, now Missouri University of Science and Technology :isadizzy: Anyway, I have yet to learn to use a slide rule (I'd like to, oddly enough). I've held one :d I'm in the process of chasing a degree in Mechanical Engineering.:running:

Ivan
November 16th, 2008, 21:02
Hi P&W,

You quoted my original post. I went back to edit when it started sounding too much like an off topic argument. 200 Meters out DOES pull a lot of velocity off a .30 caliber bullet. It makes it behave more like a .308 Winchester up close.

Seems like we are all posting at the same time. Gwynedd, I just saw your post when I began mine. I was wondering a bit how a specialist in fiber technology would get involved with armour but it all makes sense. I would love to discuss the topic offline, but realise that I probably have nothing to contribute so it would be more like attending a lecture.

Great use of logic in your description of elastic armour to your client. Folks sometimes get caught up in the details without remembering WHY they were in the game to begin with.

I play a lot with small arms, but my direction is more toward getting the best possible accuracy with no consideration of terminal effect. Velocity is useful to me only to get the best trajectory and range and hopefully consistency. I tend to load ammunition toward the middle of the velocity range because that is generally where the best accuracy is and also because it should produce pretty much the expected results with a particular cartridge.

As you can see, I am reasonably serious firearms enthusiast and a mention of the subject will almost certainly get some kind of response from me.

In this case, the only useful information I can point out is that your potential threats may include a few more cartridges: 8 mm Mauser, and 5.56 mm rounds with a 62 grain steel core bullet (SS109?). I believe the 8 mm (or 7.92 x 57) was used extensively in Yugoslavia not too long ago. The 5.45 even with a steel core had fairly poor AP performance IIRC.

Good Evening.
- Ivan.

Skyferret
November 16th, 2008, 21:40
Ivan: I used to be somewhat of a gun slinger myself. It's been a while since I have been out to the gun range to make some noise.

I used to reload a lot of 12 gauge. Here's one trick I did a couple of times. I made solid plastic slugs from PVC tubing loaded in 3" hulls. Being such a light projectile, I must have been getting some crazy velocity at close range. A 2X4 at 60 feet and it went clean through it. Or a milk jug full of water, grab an umbrella, 'cause it exploded.

Why? Why not. It was kinda fun.

Johnny
November 16th, 2008, 22:11
~S~ All,

Rubber, would be a good way to slow or stop a round, but it would take so much no one would or could use it. Even with the steel breast plated Kevlar, most people stop wearing them after a while. They shift, they rub, they make you sweat like a pig. Bad guys shoot for the head. You could die from a scratch. It all seams like a great waist of time an money. You make a better vest, they make a better bullet. Tanks are not really bullet proof.

Work on robots and have the soldiers sit in front of computers in air-conditioned bunkers. Or better yet, bring out the neutron bomb and kill them all.

War, I know and there has to be a better way. If humans were honorable people and we had a dispute, we could each sent one champion to fight to the death. Not tens and hundreds of thousands of our finest. H:censored:, we elected our politicians to server us. Make them serve half their term in a war zone. Make them serve there whole term there and let some honest person represent up in Washington.

Oh well, time to return to my rubber room where I am safe as long as I where my aluminum foil hat.

j:isadizzy:

Gwynedd
November 17th, 2008, 05:50
I'll try to answer two at once here.
That was a frangible, Skyferret. The state of the art now uses either brass and nylon composite that disintegrates shortly after impact, or a clay/polymer composite that is the most God awful hollow point you can imagine. It more or less explodes in the target. The one you made would be effective at close range, but if it did not kill the target, the ER would never find all the fragments because they don't show up on X-ray or echo in MRI.
Ivan, if I can post a PowerPoint here in some way, I will be glad to, but I don't know how. Is that possible? Also, I would be glad to talk off line. My public e-mail is gwen_thomas2000@yahoo.com
And I agree that other threats are important, but public universities don't buy guns for professors. I have to get my own. Most people are very stunned when they learn that a church lady professor in town owns over 20 firearms and ammunition, so I try to avoid the topic. The last 8mm Mauser I saw here was about $350, but it was in a shop frequented by KKK and drug dealer types and they hang pictures of Hitler in there. I'd rather not go in there without Obi-wan Kenobi. There is a new Academy Sports here in town near the Sam's Club and they have ads in the Sunday paper that look like price ranges I could afford about once a year. I guess I should get a 5.56, but the new 0101.06 NIJ armor standards call for a .357 Sig, and I don't have one of those. I need to find out if my 7.62 x 25 CZ52 can fill that role before I buy anything else.
And before you ask - I do keep them locked up and ammunition separate. ...Mostly.


Ivan: I used to be somewhat of a gun slinger myself. It's been a while since I have been out to the gun range to make some noise.

I used to reload a lot of 12 gauge. Here's one trick I did a couple of times. I made solid plastic slugs from PVC tubing loaded in 3" hulls. Being such a light projectile, I must have been getting some crazy velocity at close range. A 2X4 at 60 feet and it went clean through it. Or a milk jug full of water, grab an umbrella, 'cause it exploded.

Why? Why not. It was kinda fun.



Gwynedd, I just saw your post when I began mine. I was wondering a bit how a specialist in fiber technology would get involved with armour but it all makes sense. I would love to discuss the topic offline, but realise that I probably have nothing to contribute so it would be more like attending a lecture.

In this case, the only useful information I can point out is that your potential threats may include a few more cartridges: 8 mm Mauser, and 5.56 mm rounds with a 62 grain steel core bullet (SS109?). I believe the 8 mm (or 7.92 x 57) was used extensively in Yugoslavia not too long ago. The 5.45 even with a steel core had fairly poor AP performance IIRC.

Good Evening.
- Ivan.

Johnny
November 17th, 2008, 08:30
~S~ G,

Empty guns are good when uses as paper weights. I have on automatic that has no round in the chamber, because of a known safety issue, with this brand name. Other then that, they are all loaded to the max.

Sorry to hear about the KKK. I am not sure which verity you have there, they are all different or should I say just confused about what is important. They busted a group of the white supremes kind near here a week or so ago, in Bogalusa, LA. The local KKK disowned them. The local KKK held a public rally last month at the Pearl River County Courthouse. I guess it was a membership drive. Most people went on about their own business, like they were not there.

As I recall, C.S.A General Nathan Bedford Forrest was the first Grand Wizard of the KKK. At that time they were anti-black and anti-Carpet-Baggers. Throughout there history they have been anti-everything. Irish, German, Italian, Japanese, Jewish, Commies, yadi yadi yadi. In other words, it is not just a black thing. Bigot de jour. The way I hear it the worst KKK bunch is in Missouri, but you would have to check with P&W, if he knows.

Forget the bigotry and get the Mauser. Academy is to high, check out the pawn shops and gun shows. Wal-Mart has some good prices on long guns. If you really want a good deal, get a FFL and buy wholesale.

j:isadizzy:

Johnny
November 17th, 2008, 10:22
~S~ G,

They will never un-arm everyone. I think I have a solution to your quest for the perfect weapon to use in your test. http://www.amazing1.com/electric-guns.htm

Just a thought.

j:cost1:

Dave Cumming
November 17th, 2008, 12:06
Reading this post with great interest. Over the last year i have been providing some firepower for a friend of mine who is developing better bulletproof glass. He used to be an ATO (I don't know the US translation but in English he was a bomb disposal officer). Retired, burnt out about 8 years ago and taken over the family chemical company. He was looking at using nano particles in plastics to improve the energy asorbtion between the sheets of glass for car windscreens. The glass does a good job of destabilising the bullet and the plastic polymer then absorbs more energy. Several layers of plastic and then some sheeting at the back to hold it all together. To pass the tests he had to put 5.56 and 7.62 nato rounds into the area without any fragments getting through and without losing too much visibility. I provided the 7.62 and a friendly Police Firearms instructor provided the 5.56, military providing the range (especially as they like bullet proof things!). Fascinating how easy it is to stop a 5.56 - much harder for 7.62.

Ivan
November 17th, 2008, 15:57
Hello All,

Dave, I am glad you were paying attention. I can't think of a better addition to the discussion.

Gwynedd, There are LOTS of Yugoslav Mauser 98s on the market now. I believe the going price is in the $150 range. They are pretty close to a German K.98, but are about a half inch shorter in the receiver and thus not representative for my purposes, but as a launcher of 7.92 x 57 mm rounds, they should work well. I don't believe the 7.62 x 25 mm is a good substitute for a .357 Sig. Reasons are: The bullet is too small diameter and light and I don't believe they are typically loaded with the same hollow-point / soft-point assortment as you find in 9 mms. Yes, the .357 Sig is really a misnomer; It really is a high power bottle necked 9 mm with .355 diameter bullets. As such, I believe you can duplicate its performance with 125 grain bullets if you can find a lever action .357 Magnum carbine like a Marlin. I believe the Cowboy action folks tend to have those. The normal .357 Magnum out of a handgun probably won't achieve the velocity you want, but you can get the extra velocity out of a rifle / carbine length barrel. If the velocity is too high, back off a few yards. Now to think about it a little, your typical .357 Sig is coming out of a 4 inch barrel. If you find a 6 inch .357 revolver, you have effectively the equivalent of about a 7.5 inch auto pistol barrel and perhaps that would provide enough velocity. (I haven't checked the numbers.)

Skyferret, I've never loaded for Shotguns but do quite a lot of pistol and rifle reloading. You're going for the hyper velocity route. I go for the solid cast 450-550 grain .45 caliber bullets just loafing along at about 1400-1450 feet per second. This is not to say that I don't do higher velocity stuff, but I have never experimented with anything that would beat 4000 fps.

Hey Johnny, We already have the situation with folks in air conditioned rooms in the continental USA piloting RPVs over the war zones. Personally I would not recommend a FFL unless you understand the consequences: business hours, records keeping, potential BATF visits, etc.

- Ivan.

Gwynedd
November 17th, 2008, 17:56
Good for him, Dave. That is taking the traditional plastic laminate idea into the most advanced realm of chemistry and physics before others have done it. I hope he is very successful with the idea. I would love to see him apply thin aluminum oxynitride layers in place of glass, if he is able to get it. http://www.livescience.com/technology/051018_new_glass.html


Reading this post with great interest. Over the last year i have been providing some firepower for a friend of mine who is developing better bulletproof glass. He used to be an ATO (I don't know the US translation but in English he was a bomb disposal officer). Retired, burnt out about 8 years ago and taken over the family chemical company. He was looking at using nano particles in plastics to improve the energy asorbtion between the sheets of glass for car windscreens. The glass does a good job of destabilising the bullet and the plastic polymer then absorbs more energy. Several layers of plastic and then some sheeting at the back to hold it all together. To pass the tests he had to put 5.56 and 7.62 nato rounds into the area without any fragments getting through and without losing too much visibility. I provided the 7.62 and a friendly Police Firearms instructor provided the 5.56, military providing the range (especially as they like bullet proof things!). Fascinating how easy it is to stop a 5.56 - much harder for 7.62.

Pratt&Whitney
November 17th, 2008, 18:42
With the V-22, are you forced to look at repeat fire? If I remember this right... ceramic body armor plates are a one hit use. Kevlar and similar vests would be better for repeat hits, but probably not on identical points of impact...

With ceramics, we were talking today about using crystal changes in the material to actively repair cracks and fractures as they occur. Of course, EVENTUALLY, this will run out of material, and stop functioning, leading to a brittle failure.

Unfortunately, I don't think any of this would be terribly effective against RPG's, which I would venture to say are a far more realistic threat to low flying aircraft.

Gwynedd
November 17th, 2008, 19:00
Thanks, Ivan.
I will have a look at the Mauser model that you mention and see if anyone in town has one. The maximum energy density of a 7.92 x 57 round is 89.2 Joules/mm^2 compared to 86.4 Joules/mm^2 for the 7.62 x 54R such as the Dragunov rifle uses. Good call. If the Navy and Marines want it and can sacrifice the extra weight for that level of protection, I will spring for it. BTW, .30-06 energy density is 83.8 J/mm^2, so it is not a player.
Insofar as the .357 Sig is concerned, the standard prescribes 6 hits with 125 grain, FMJ flat nosed at 1470 fps. http://www.ncjrs.gov/pdffiles1/nij/223054.pdf That equates to an energy density of 11.78 Joules/mm^2 . The 7.62 x 25 carries an energy density of 12.25 Joules/mm^2, so I would judge the smaller, faster round more potent against armor. It goes without saying that a hollow point round is very easy to stop in armor compared to a rounded or pointed solid projectile.
And finally, I don't want a Federal Firearms License or a Class III permit. I don't even shoot the rifles myself unless I have to. I already took three bullet ricochets from Russian 7.62's in my body so far doing this stuff. I just want to make armor that works, not shoot stuff. I don't enjoy that part. I enjoy it a lot less when I get shot.


Hello All,

Gwynedd, There are LOTS of Yugoslav Mauser 98s on the market now. I believe the going price is in the $150 range. They are pretty close to a German K.98, but are about a half inch shorter in the receiver and thus not representative for my purposes, but as a launcher of 7.92 x 57 mm rounds, they should work well. I don't believe the 7.62 x 25 mm is a good substitute for a .357 Sig. Reasons are: The bullet is too small diameter and light and I don't believe they are typically loaded with the same hollow-point / soft-point assortment as you find in 9 mms. Yes, the .357 Sig is really a misnomer; It really is a high power bottle necked 9 mm with .355 diameter bullets. As such, I believe you can duplicate its performance with 125 grain bullets if you can find a lever action .357 Magnum carbine like a Marlin. I believe the Cowboy action folks tend to have those. The normal .357 Magnum out of a handgun probably won't achieve the velocity you want, but you can get the extra velocity out of a rifle / carbine length barrel. If the velocity is too high, back off a few yards. Now to think about it a little, your typical .357 Sig is coming out of a 4 inch barrel. If you find a 6 inch .357 revolver, you have effectively the equivalent of about a 7.5 inch auto pistol barrel and perhaps that would provide enough velocity. (I haven't checked the numbers.)
Personally I would not recommend a FFL unless you understand the consequences: business hours, records keeping, potential BATF visits, etc.

- Ivan.

Gwynedd
November 17th, 2008, 19:25
Military body armor today consists of two variants: the SAPI (small arms protective insert) plate and the ESAPI (enhanced SAPI). SAPI is a multi-hit B4C face design to withstand FMJ. ESAPI is technically good enough at one hit AP capability. They can take more in certain conditions.
In this project we have stricter boundary conditions, though. Again, the problem we face is power to weight ratio, and the contractor will tell us their needs and limits. I don't want to get specific on a board like this because I don't know who is reading it besides us. Suffice it to say that indeed there are more things than are dreamt of in use now. I just hope some of it works.



With the V-22, are you forced to look at repeat fire? If I remember this right... ceramic body armor plates are a one hit use. Kevlar and similar vests would be better for repeat hits, but probably not on identical points of impact...

With ceramics, we were talking today about using crystal changes in the material to actively repair cracks and fractures as they occur. Of course, EVENTUALLY, this will run out of material, and stop functioning, leading to a brittle failure.

Unfortunately, I don't think any of this would be terribly effective against RPG's, which I would venture to say are a far more realistic threat to low flying aircraft.

Johnny
November 17th, 2008, 19:54
~S~ All,

EOD I think = ATO, not sure anymore.

I am told that there are speed limits that cannot be exceeded. The speed limit for muzzle velocity for firearms is said to be 2,000 km a second. That would be 6561679.790026247 feet per second. I am not sure what could fire a projectile at that speed, but I want one. I really have no idea what could stop that.

When I was young I could shoot birds out of the sky with a BB gun. Later it was targets at 1,000 yards without telescopic sites, using a M-14, 7.62 NATO round. You could fire the round and look through your spotter scope and see the vapor trail as the hot bullet moved through the cool air and into the target. That seamed to be a long time, but was probably 2 seconds +/-.

j:cost1:

Gwynedd
November 18th, 2008, 05:59
2000 km/sec? That is really fast, Johnny. In fact, it's about 270 times faster than the space shuttle in orbit. I guess the main limitations are the availability of a propellent that strong, the pressure a barrel could endure during acceleration of the projectile, the friction generated during acceleration (it would no doubt melt both barrel and bullet at that speed) and the aerodynamic drag (at that speed it would be more than if the bullet hit a planet made of pure diamond.)
Thanks for the link to the amusing science toys. Did you know that the Japanese actually did try to make a microwave gun in World War II? It was unsuccessful because it loses too much power quickly, but it shows how ingenious they were.
I never saw a vapor trail on a bullet. That must be fascinating. Obviously my eyes are nowhere near as good as yours. I just keep the prescription up to the level for me to pass my Class III flight physical every other year.
Thanks and have a good day. :naturesm:


~S~ All,

EOD I think = ATO, not sure anymore.

I am told that there are speed limits that cannot be exceeded. The speed limit for muzzle velocity for firearms is said to be 2,000 km a second. That would be 6561679.790026247 feet per second. I am not sure what could fire a projectile at that speed, but I want one. I really have no idea what could stop that.

When I was young I could shoot birds out of the sky with a BB gun. Later it was targets at 1,000 yards without telescopic sites, using a M-14, 7.62 NATO round. You could fire the round and look through your spotter scope and see the vapor trail as the hot bullet moved through the cool air and into the target. That seamed to be a long time, but was probably 2 seconds +/-.

j:cost1:

Johnny
November 18th, 2008, 07:48
~S~ G,

No more flight physicals for me. I am glad CFS does not require one. Class three, let me guess: Jets?

Before my wife bought the big screen, I needed three pairs of glasses for the computer. My next appointment for glass is next month.

As for speed: Earth's escape velocity is 11 km/s. Proof that Earth sucks.

Good luck,

j:cost1:

Ivan
November 19th, 2008, 13:06
Hello Gwynedd,

The measurement of Joules per mm^2 seems to me to be an incomplete picture / summary of the penetrating ability of a projectile. If one takes it to the extreme, a buffalo rifle with a fairly large cross section would seem much more dangerous than a smaller projectile with the same energy per cross section. This is why I wonder if a 7.62 mm pistol bullet can adequately simulate the penetration of a 9 mm bullet. I figure similar bullet construction and diameter, similar velocity should yield similar results.

Also, What bullet weights are being used for the 7.62 x 54R and 7.92 x 57? The higher bullet weights in both would seem to me to be more dangerous. With the 7.92, I have seen 153 grain concave base bullets from China and 196 grain boat tail bullets from Portugal. There is a radical difference in retained energy between those two bullets. Consider also that a rotorcraft will most likely attract small arms fire from 100 to 500 yards away, so retained energy is important. If someone is taking pot shots at you from 10 feet away, you have more problems than armour is going to solve.
:kilroy:

Hi Johnny,

I also usta shoot high power. You can see these bullet traces even at short distances such as 200 yards without optics. It helps to be directly behind the shooter on a very humid day. A spotting scope helps too. My experiences spotting these traces has been with M1 Garands using standard M2 Ball. (Not that different from a M14.) I AM extremely familiar with the operation of the civilian equivalents to the M14 though.
:icon_lol:

I believe the actual limiting velocity of a "FIREarm" using some kind of chemical propellant is more on the order of 20,000 fps because the expanding gas from the propellant doesn't go any faster. I need to check my sources on this one though. Do you still play with the high power rifles? That could be an interesting discussion.

Later.
- Ivan.

Dave Cumming
November 20th, 2008, 10:41
Gwynedd, thanks for the website. Looks fascinating & I've passed it on for comment. My friend most likely won't look at it because 1) it's too expensive and as a producer he wants to keep costs down, 2) cannot make it large enough for car windscreens, 3) probably cannot be made easily, 4) being more durable, he loses maintainance and rebuild work! He told me that the existing stuff has a usable life of about 1 year as the windscreens delaminate from the sunlight and the cars are worn out from the weight of all the additional armour. Good for a producer.

I was also curious about your energy figures for the different rounds and was going to look at how penetration figures are calculated. I don't normally worry about thing like that as I am a precision shooter and not a hunter. But for Practical Pistol they measure the power factor using the velocity x the weight (but not velocity squared!). Our UK ranges have just been limited by muzzle velocity using momentum (mass x velocity) which acts against blackpowder. According to our Government a .577 black powder rifle is more powerful than a modern 5.56 or 7.62 round!

My penetration queries were started last time I was testing the bullet-resistant glass. My friend had also filled some beakers with his polymer compound, a different beaker for each type he was testing. Without the glass in front we didn't know how far any bullet would penetrate but the best polymer is the one with the least penetration. I was using .357 magnum through a carbine and they all showed less than an inch penetration. I hoped to try more pointy bullets but as we have a poor selection here (if you believe that UK is bad you should try Belfast!) and tried some 124g 9mm heads as they are the pointiest I can find. I have now discovered that 0.001" difference in bore diameter has a great difference on accuracy!

Ivan
November 20th, 2008, 17:04
Hi Dave,

I guess what your ranges and the IPSC base things on is momentum. Not unreasonable when calculating hitting power of pistols but a little strange when one is trying to calculate how far things will go. If you really want to get an idea how far things fly, I believe Julian Hatcher covered things pretty well (at US Government expense) in "Hatcher's Notebook".

.577-450 Martini-Henry, right?

If you were trying to get some nicely penetrating .357 bullets, I would go with some hard cast conical bullets perhaps out of wheel weights. That must be some pretty amazing stuff to stop a .357 Magnum carbine round in less than an inch of penetration. We had a fellow at one of our ranges display a laminated Kevlar sheet with various handgun bullets embedded in it. The caliber I remembered from that exhibit was the M1 Carbine (110 grain .30 cal bullet at 1980 fps) because it went clean through!

I believe our interests for firearms accuracy are pretty similar. Energy isn't particularly important, but velocity and consistency in instrumental velocity are quite important to predict potential accuracy and trajectories of various ammunition. For a while, I tended to chronograph just about everything I handloaded and quite a lot of factory ammunition as well. It revealed a lot about claims versus reality.

- Ivan.

Gwynedd
November 20th, 2008, 21:26
Hi, guys. I will get back to all of you on these questions as soon as I can. I just got in (midnight) from a presentation in Atlanta. I have 15 exams to collect and grade tomorrow and 2 new armor patterns to lay out and assign for assembly to my girls before I can come home tomorrow night and take a breather. I think a glass of red wine will be in order before I start on this, if you don't mind.

Johnny
November 20th, 2008, 23:47
~S~ All,

I think G's weapon should a Black Powder rifle. They are cheep enough and I think use many different projectiles and the power can be regulated.

Ivan, I was doing a little sighting for people before hunting season, but when you put three rounds in the same hole and they can't, it ticks them off and blame you for not doing it right. I use to shoot NRA National Match and my favorite place was "The Thousand Yard Line at Oak Ridge, Tennessee." That was always done on Sundays. The best I did was a 95. Ten shots, a ten and a five ring. I do not recall the X count. We used peep sights and the winners used Telescopic sights, with the x count determines the winner. Every time we shot it we would receive a silver pin with the "Le Grand Carbine" on it.

My long weapon of choice is the Marlin SS 22 mag. with a nylon stock. Hand gun 9mm S&W 659. In the afternoon I am going to look at another one in blue steal. Best weapon I ever owned was a H&K 93, but it was to heavy. It went in Katrina, with a lot of other stuff. A friend had a S&W 40 that I saved for him. After Katrina it was junk, but a year later no one could tell. He gave me a .380 that no one could cock and as such was never fired. I managed to fire it once and the shell casein jammed it. I shortened the spring a little. It cocked a little easier, but still caught the shell casein. If I get the chance I will take a little more off of it then turn it into a Pocket Pistol Competition Special.

Dave, I have shot at people in cars and I have seen what a lot of others have done. It is almost imposable to penetrate a wind screen, because of the angle at which it strikes. Anything around 45 degrees or less the bullet strikes and continues up or down the glass. I went on the Screen of a drive-by where the perpetrator pulled up next to the victims car, and shot him through the front passenger side glass. The perpetrator drove off and the victim was carried into the house. 911 was called and EMS could not find anything but a red spot on the right side of his chest. The perpetrator used a snub-nose .38 and the glass slowed the bullet town enough that it did not penetrate the victims shirt.

Well enough war stories,

Time to Sleep, per chance to dream.

J.:isadizzy:

Ivan
November 21st, 2008, 02:41
Hi Johnny,

The problem with a black powder rifle is that the velocity is so limited as is the diameter of bullets. I don't believe I have ever seen a black powder rifle smaller than a .40 caliber or with a claimed velocity over about 2200 fps. Besides, if you reload, just about ANYTHING can be tuned down. I once did an experiment with loading each round with .3 grain more powder than the last (based on an article by Creighton Audette) with velocities in the 2200 fps range out to about 2600 fps. The shot pattern (and I really can't call it a group) was quite interesting to observe. Each round's impact was noted and all velocities were chronographed.

On occasion, I usta do the same for people at the range but mostly with handguns. I don't believe I ever had anyone get upset that their gun was shooting better than they were. Then again, THEY were the ones coming to ask me to check out their gun.

As for high power shooters, I believe they are an interesting bunch. I have had MANY folks show off targets to me that had about 40 or 50 holes in a 6 to 8 inch diameter circle that were making claims as to how one could discern a tendency or pattern to the shots. I have had folks shooting M1As show me targets with about a 3 inch group tell me how their rifle was shooting sub-MOA but they had just pulled a couple shots.
I figured out a long time ago that at least for me, serious accuracy testing with a high power rifle required a scope. FWIW, I was scoring 93's in sitting and prone rapid fire at 200 yards with a gun that later proved to be capable of only 3.5 inch groups at 100 yards, but that was a LONG time ago. (Iron sighted rack grade M1 Garand with Vietnam era Lake City M2 Ball.)

A S&W 659? I shot one about a month ago along with a few other assorted toys. This pistol impressed me as being pretty well made, but extraordinarily heavy. Know where to get magazines for them? I would love to get a S&W 639 if I could find one. I prefer Stainless and the 39's seem to fit my hand better. All the H&K / CETME rifles impress me as being a bit chunky and heavy, but quite good designs. I have fired a HK 91 quite a lot but never owned one. Only tried out the HK 93 a couple of times and can't remember much about it. I wish they had longer barrels to cut down on the muzzle blast and to increase velocities.

- Ivan.

Johnny
November 21st, 2008, 08:19
~S~ Ivan,

I had matched the highest score ever shot with every light weapon the Army had at that time, except the M1. The one I had was a hunk of junk. I received a Sharpshooter medal for that and expert for everything else. When I was on the rifle team, we did all of our own work on the weapons. We had national match M14's and one day a week we would go to the range with 1,000 rounds of National Match ammo from Lake City. There was usually a Match somewhere every month and we went. Shot groups were usually just that, groups. At 500 yards they were the size of a half dollar. The count was in X-rings. If you were going to screw-up it would be at the 500 yard line. Almost everyone scored a perfect score, I did see a three way tie once. They all had all X's and had a shoot off. T am sure the gut who won was Blankenship, and I think his first name was Paul, but we are talking 40+ years ago.

When I signed up, it was to be a telephone lineman in New Orleans. In basic this guy from the 101st came a talked to us and I signed up to be Airborne. I figured I would be an airborne telephone lineman in New Orleans. Wrong. I became Airborne Unassigned and I belonged to them. I never had to volunteer for anything again.

When I was with the 82nd, my Platoon Sgt. came in and Said I was going to be the new Operations Clark and I was sent to typing school. It was the worst job I have ever had, but I found out that clerks run the army. You take a thirty day leave and when you get back you still have thirty days on the books. Some guy gave me problems and he received orders for Germany. He came to me and I had it changed, but his pay still went to Germany. Non of this was any of my doing, clerks look out for each other and make rank faster then anyone else. So I arranged to be sent to a Pathfinder Unit attacked to the 31st Infantry at Ft. Rucker, Alabama. There was a waiting list and to kill time I started hanging out at the indoor range and the rest is history.

You now when you type 120 words a minute, the Army sends you where you are needed. I was assigned to the 11th Air Assault which became the 1st Calvary and then sent to Vietnam as a snipper.

My DD-214 states I was a Radio Telephone Operator.

Well later,

J.:isadizzy:

Ivan
November 21st, 2008, 19:12
Hello Johnny,

The accuracy you were getting from M14s is pretty spectacular. If we figure that a Half dollar is about 1.25 inches in diameter, you would be holding 1/4 MOA out to 500 yards. My results have been much less impressive: about 5/8 to 3/4 MOA for 5 shots, and about 3/4 MOA to 1 MOA for 10 shots. Best reloads have been with 168 grain bullets seated to 2.82-2.83 inch OAL with IMR 4064, Winchester 748, or IMR 4895 to achieve 2575 to about 2625 fps instrumental at about 7 feet from the muzzle. I tie a string to the chronograph and use it to measure out distance to the shooting bench when I am setting it up. Because I usta chronograph from the same shooting ranges, I also put little lines of nail polish on the camera tripod to make the height consistent.

I have never had much luck with the military M118 173 grain bullets. The M852 "Not for Combat Use" stuff with the 168 grain bullet does just a slight bit worse than my handloads, but Federal .308 Match does slightly better.

I wouldn't mind discussing what was done to your M14s to make them shoot so well, but it seems beyond the scope of a public discussion.

- Ivan.

Johnny
November 21st, 2008, 22:59
~S~ Ivan,

It was over 40 years ago, 1964-65, as I recall it went like this:

When we received a new set of weapons the numbers were sequential ending in ---00001 up. The hole in the peep sight was about half the size of a normal one and the clicks were in half clicks The first thing that we did was take it apart and clean it. Every where the weapon touched the stock we hollowed out the stock, using a drill, down about a quarter inch. So it looked like a trench around the edge of the stock. We filled the holes with fiberglass and put the weapon back together and let the fiberglass harden. They would probably use epoxy today. Where the hand guard met the support strips of inner tube were place. After that the weapon was finished, it was never really cleaned, just wiped down and lightly oiled and a patch run down the barrel, after each use. The next year you were issued another one and would have to do it again.

The hard part was recording every shot in your log book. During matches that was done by the spotters or you could use your target.

Windage was done by dropping some grass from your shoulder. I was told by the guys from Panama they use rocks.

Later,

j

Ivan
November 22nd, 2008, 03:15
Hi Johnny,

I was figuring it was a bit more elaborate than that. The process has gotten a bit more refined now from my experience. Instead of fibreglas, some folks use Marine-tex. I prefer Brownell's Acraglas-Steel. It is an epoxy filled with very finely ground stainless steel. I have thought about Devcon Titanium filled epoxy, but not used it yet. The problem is that final processing requires some grinding of the stuff that overflows and Titanium eats normal steel cutters.

Glass bedding for this gun happens in a multi step process. I believe the 5 pillar bedding process developed by Mr. Reid Coffield of Brownells is the best idea but have not used it yet. It basically involves drilling tunnels between the upper bedding areas and the lower through the stock side walls and from the rear horseshoe down to the rear of the trigger assembly and filling with the bedding material. The idea is that wood compresses and bedding material doesn't, so put pillars to take up the compression force.

The stock liner is relieved to allow the legs of the receiver to sit enclosed by bedding material rather than hit the stock liner. Some folks remove the stock liner entirely which I believe is a bad idea because the magazine well then doesn't have a nice steel liner to prevent accidentally chewing up the stock from below.

The Gas system is unitized with the front band and the stock ferrule is polished. The USAMTU process was to anneal the gas cylinder and band and drill through the spindle and cylinder from the back and hold everything in place with a couple hex screws from the back. I have also seen the parts brazed together and tack welded together. I prefer the last two because they leave the gas-cutoff functional. The brazing looks better IMHO. I have also shot guns that did NOT have the gas system modified and did not shoot noticeably worse.

The spring guide is modified either by welding a rod to replace the stamped part that the spring coils over or these days by a piece from Brookfield Precision Tool. The idea is to have a spring guide that is a larger diameter and round so that the spring does not kink up.

The whole gas system is then assembled and gas cylinder lock is then adjusted so that it bottoms out on the threads at 6 o'clock. Shims are used between the barrel shoulder and the gas cylinder to adjust where the lock bottoms out.

The flash suppressor is reamed with a taper so that rain gathering at the bottom will not touch a departing bullet. I have a different idea as to how this should be done, but haven't found anyone to do the machining and welding to test out my theory.

Handguard is held off the barrel with a small rubber washer or piece under the clip. The front of the handguard may be epoxied to the front band. The handguard should NOT touch the barrel or stock in any way. On M14 Heavy barrels, it may be necessary to grind off the underside of the ridges on the handguard to clear the front of the barrel. On standard weight barrel (why would we use these on a target gun???), there will be clearance. On a medium weight barrel, there should also be plenty of clearance.

After initial assembly, there is another adjustment I found in a Marine Corps manual which seems to improve things. The operating rod should bottom out against the gas piston. There will be a small distance (about 3/32 inch) from where the op rod stops and the roller on the bolt. Test this by unscrewing the gas plug. With a .308 Go gauge in the chamber (to substitute for a max size round) check contact distance between op rod and bolt roller. Cut the back of the gas piston until the gas plug only pushes the op rod about 1/32 or less off the back of the bolt roller. This increases the time between when the op rod starts moving and when the bolt starts to unlock. Details regarding testing are too elaborate to describe here.

Unless this is a stainless barrel, you might want to mask off the barrel (without gas cylinder in place) and spray paint the bottom of it with silver engine paint or some heat resistant paint. The idea is to prevent rust from gas fouling from the back side of the gas cylinder. Silver shows up fouling pretty well for those complete disassembly and cleanings.

There are two sizes of NM rear sight aperture. .0520 and .0595. My preference is for the 0.0520. These sights have a notch on the back which indicates the direction of adjustment. Rotating the hood so that the notch goes from top to bottom would lower the sight by 1/2 MOA. The military uses a sight base with finer threads to allow 1/2 MOA adjustments per click. I think these bases have "NM 2/A" markings or something similar. Some commercial manufacturers grind off the detents on the windage knob and put a small cavity in the right side of the receiver under the sight for a spring and ball bearing to index on the notches the cut into the back side of the windage knob. IMHO either one works well enough. Some folks like to cut the lower part of the aperture so that when elevated high enough, the entire aperture comes out of the gun. This is to allow for aperture changes on the range without having to disassemble the entire rear sight. I prefer not to do this.

That's pretty much the process as I remember it. There are a quite a lot of notes on alignment, clearances and checks left out. BTW, for those who might want to actually try this, I accept no responsibility for anything YOU blow up! This is intended as a "War Story". Treat it as such!

- Ivan.

P.S. Remember to cut or grind on the cheaper replaceable part!

Johnny
November 22nd, 2008, 07:17
~S~ Ivan,

I think that could have been said a little bit different.

Polishing the surfaces of lesser quality parts will not only save money, but insure you of a better operating system.

:bs:
J.

Ivan
November 22nd, 2008, 18:18
Hey Johnny,

Not quite sure what you are disagreeing with. All I am saying is when given a choice of cutting on a replaceable part or a non-replaceable part such as the receiver, cut on the replaceable part. There are a few exceptions to this rule such as fitting a bolt to the receiver. The bolts are hardened so you really don't have much of a choice. With other parts such as clip guides, bolt stops, trigger housings, etc., the part is cut to match the receiver.

I have seen Armscorp receivers that could not take a GI Op rod in the side rail. The right way to fix things here would have been to re-cut the op rod rail. The cheap way was to cut the tab on the op rod so that it would fit into the rail. I have seen an Armscorp receiver that would not take a S&K scope mount because the notches and rails for the scope mount were in the wrong place. (Just hate it whennat happens!)

I have seen a Federal Ordnance receiver that did not have the two receiver holes for the rear sight on the same axis. Another receiver had one receiver lug machined so far back that it could not contact the bolt lug on that side. With that rifle, I used Post-It notes to "bed" the receiver into the stock. Without a pair of scissors to trim the Post-Its, the rifle looked pretty goofy with torn up yellow paper sticking out in various places, but the accuracy improved from 4 inch groups at 100 yards to 1.5 inches at 100 yards. The owner of the rifle told me months later that he never moved the Post-Its but trimmed off the pieces that stuck out!

Johnny, to some extent you are correct that polishing a lesser quality part will do as well, but the problem here is that with the lesser quality part that is generally softer, the precise fit may not last as long. Next time you handle a M14 / M1A, look at the rear of the spring guide that fits into the notch on magazines. Most I have seen show obvious wear from magazines being inserted. This is what happens when you use the original GI spring guide even if you weld a round rod to the front to make a better guide. With a Brookfield guide rod, you spend $25 or $30 for the part, but it doesn't require labor for cutting and welding and is a hardened part.

FWIW, the first rifle I "glass-bedded" was done with a material called Micro-bed. It worked but the bedding had small voids (bubbles) in various places. Still, the bedding job with this poor material and workmanship lasted almost 15 years before needing to be redone.

These days, the price of good quality parts and materials isn't very high when compared to the amount of free time I have to do the work.

- Ivan.

Johnny
November 22nd, 2008, 21:55
~S~ Ivan,

Actually, when I wrote that I was thinking about the a firing pin that I need to check. Not that it gives any problems, but I was told that it could. They are known to have slag and burs on them. Cheep gun, but that makes it fun to play with. I saw what others have done with the same pistol on the Internet. It is a Jennings and sells for $35.00 FFL price, $150.00 to $175.00 range to us. There is a dealer near by that said he would charge $35.00 to receive anything I ordered and paid for. I am not sure what he meant. My wife thought if I found it somewhere I could pay him for it + $35.00 and he would order it for me.

I have about twenty projects going, counting the CFS Dam. Looks OK but can not get to sit on the ground level. The AF99 Flight Dynamics Editor can not find CFS. Padlock view is at ground level and that puts you in a valley between two other dam sections. Almost finish My hydrogen generator for the truck, but with gas under two bucks, the incentive has lessened. Want to start working on a super coil gun. Have ten shelving units to be put together and do not have any place to put them. Plus things I do not want to think of.

Well we fly and die tomorrow, you could stop by and give smilo and Hubbabubba heath attacks. :costumes:

Later,

j

Ivan
November 23rd, 2008, 02:47
Hello Johnny,

I am actually quite familiar with a Jennings J-22. I have messed with a couple on various ranges. The general problem I have seen with those is that the recoil spring tends to be a bit on the heavy side and sometimes (usually) the guns don't function with standard velocity .22 LR ammunition. High Velocity stuff seems to work most of the time if the guns work at all. I have seen guns which were dry fired a bit and the firing pin will raise a little ridge on the upper side of the chamber and also screw up the bolt face. The bolt face part is hard to fix because the slides (and frame) are zinc alloy (pot metal). The chamber wasn't hard to "fix". Just take a pocket knife and cut off the ridge! The metal is THAT soft!

Personally I don't like to mess with stuff made of zinc alloys. You can "fix" things, but they don't stay fixed because the parts wear so badly. I have a couple gun projects which are on-going because I can't find the parts. I have some where I have the parts but am too lazy to actually start because I KNOW they will be very high labor. I have a very nice .22 pistol that has a worn out firing pin. (15,000 rounds will do that!) I have a spare, but it needs to be fit to the gun and THAT isn't all that easy. That .22 pistol would put 10 rounds of Target .22s into a 3/4 inch group at 25 yards. High Velocity stuff went into 1 inch groups if the ammunition was any good. I SHOULD fit an extended ejector to my wife's pistol so that ejected cases are thrown a bit further. There is one pistol that I messed around with the recoil spring assembly but have not test fired to make sure it still functions reliably....

Regarding CFS projects, I have about 15 incomplete ones at the moment. I figure I have publicly released less than half of the projects I have started and just about all the releases I have done have had major updates since release. Why are you doing a CFS Dam? What kind of AIR file is a Dam sposta have? How does one fly a Dam?

I believe I finally finished the AIR file for my B-25C Mitchell. The model still needs tweaked a bit with a signature like the one you have in your AA tank and the textures need to be finished.

Partial summary of the flight test results (from memory) for the B-25C are the following:
267 mph at sea level
313 mph at 12500 feet
224 mph at 27500 feet
1700 fpm initial climb rate
1885 fpm maximum climb rate at 10,000 feet
best climb speed is 210 - 215 mph which seems a bit too high
service ceiling (100 fpm) is 27200 feet
absolute ceiling with 475 gallons fuel and no bombs is almost exactly 28000 feet.
2 notches of flaps should be used for take-off. I was able to get the plane off a rather short runway with 10 x 500 pound bombs and a full load (670 gallons) of fuel.
Fuel consumption is about 20% too high
Longitudinal trim is slight nose down with a 5000 pound bomb load and slight nose up with no bomb load.
I don't know that all the specs are an exact match for the real plane, but these numbers seem more or less reasonable to me except for the fuel consumption.

- Ivan.

Johnny
November 23rd, 2008, 06:47
~S~ Ivan,

My Jennings is a .380, and I have to shorten the recoil spring a little more and the rest is just cosmetics.

A dam has a regular .air file like everything else. "How does one fly a Dam?" There are just to many answerer for that. Not worth a dam, like a brick.... The dam is places with slew, and the flight saved. Mostly it is a ground target that shoots back.

A partial summary of the flight test results (from memory) for the Dam are the following:

0 mph at sea level
0 mph at 12500 feet
0 mph at 27500 feet
0 fpm initial climb rate
0 fpm maximum climb rate at 10,000 feet
best climb speed is none
service ceiling goes where you put it.

You would think with numbers like that it would be easy, but it is worst them an aircraft.

Well, I think it is time to hunt down the AAC.

Later,

j

Gwynedd
November 23rd, 2008, 09:28
Dave,
Those are good points for a consumer goods production company. US Air Force and RAF budgets are likely big enough to allow for that product, but not budgets of professors, industrial managers or bank tellers.
Okay the rest of this is going to be long and it pertains to this and other questions. Sorry about that.
The UK method of calculating bullet strength is its momentum (mass x velocity). That makes no sense to me because a human on a bicycle riding at 20 km/hr would be considered more dangerous than a 9 mm pistol round. (For the sake of example, the human and bike might be 75 kg x 20,000/3600 m/sec = 417 kg-m/sec; the 9 mm bullet might be 8/1000 kg x 400 m/sec = 320 kg-m/sec. Therefore the bicyclist is 30% deadlier than a 9 mm pistol?
Newton's actual definition is that momentum (mv) = impulse (Force x time), so the faster a bullet transfers its momentum, the more force is transferred into a collision.
By the same principle, Energy and Work are the same quantities in Newtonian physics. Energy is the equation I used earlier (Newtonian E = 1/2 mv^2, from which Einstein eventually derived E = mc^2 because light is the ultimate speed and there is no dissipation of the energy at that velocity, thus eliminating the factor of 1/2).
Now Work is a definition of energy given in Newton's physics as Force x time, so the force of Impulse you saw above must be totally absorbed in a limited distance and that distance is the time to stop the impact velocity. To find the distance, we can put the maximum allowed distance as the upper boundary condition and 0 as the lower condition. In Germany the upper boundary is 22 mm deep. In the USA it is 44 mm. (Because we are fatter? Or American women have bigger boobs? I don't know why.)
But the end result is that we know the conglomerate structure must absorb the energy of the bullet in 0.0044 meters maximum travel or the armor is a failure. This means the very minimum strength to break of the structure is defined as [(bullet mass x bullet velocity^2)/(2 x 0.0044 m)]. But we have another problem to consider. The foregoing model only takes into account Work to break along the perpendicular to the plane of the armor. We also need to consider breaking strain, and that is a function of the speed with which a force moves along a material, and that is again a function of the momentum (above), which also defines inertia. Breaking strain is defined as (length at break - original length)/original length. So let's say that a bullet hits a Kevlar filament yarn. A good representative breaking strain for this Kevlar is .034, so it has to stretch to 1.034 times its original length before it breaks. This becomes a function of how fast it will stretch that far to determine if it breaks before the .0044m limit is exceeded. So if that 9mm bullet (above) hits our Kevlar thread, what happens?
1) The filament yarn extends into an angular shape defined by the velocity of the bullet
2) The mass of the yarn can be found for any given length thanks to a numbering system used by industry called Denier. Denier defines the number of grams of mass of a yarn per 9000 meters. (No one I have ever asked knows why 9000 is used. A famous English professor at Manchester proposed a system called Tex in which grams per 1000 meters would be used. It's very logical, so industry ignores it.) A typical Denier used in Kevlar for armor is 750, which equates to 83.3 Tex.
3) Stress to break is usually expressed in grams force per denier or tex, and it is nearly a linear function (all initial modulus) for this fiber. For Kevlar 129 it is 2.38 Newtons/tex, so it will take 2.38 N/Tex x 83.3 Tex = 198.3 kg-m/sec^2 of force to break one yarn.
4) We now can find how much energy it will take to break this yarn. The yarn will break when it has been extended to 1.034 times its original length, but it is the bullet itself that is extending it. So that we don't have to differentiate the equation of the surface of the bullet ogive, is it okay just to say that the diameter of this pointed bullet lies between 0 and 9 mm? (This has to be getting boring for most people and I'm too nerdy to know when to stop.) The impacted yarn length therefore becomes 4.5 mm (.0045 meters) and it will break at a length of 0.00463 m.
5) Now we go back to the equation that Energy is Force x Length. So according to Newton, we can can take 198.3 Newtons (the unit, not the guy) x .00463 meters, and find that the yarn breaks under 0.92 Joules of energy. That 9 mm bullet's energy is defined with the velocity dependent equation E = 1/2 (mV^2), and it has 640 Joules of energy. It will require 640/0.92 = 695.7 Kevlar threads to stop it, disregarding friction, drag effects and thermal energy generation in the lead core to turn it liquid.
6) Now we see the supreme importance of cross-sectional area of the bullet in all this, because if you hold the energy quantity constant, the smaller the bullet, the shorter the breaking length of the material and the more material you need to stop the bullet!
7) The final consideration in a woven material is the number of yarns in each plane of fabric layers. For the fabric under consideration here, a very good representative number is 11 yarns/cm in a square sett (Thread count = 11 x 11). This makes 1100/meter in each direction, or 2200/m^2 (Yes, you add rather than multiply. Only 1100 will fit in each direction, so you won't get 1,210,000 crammed in there.)
8) Our bullet diameter of .0045 m is going to encounter 4.95 threads in each of the woven directions, so it has to break 9.9 per layer. Each layer will then be taking 9.9 x 0.92 Joules of energy from it or 9.1 total Joules.
9) If no other effects were involved, you would need 70 layers to stop this bullet. Obviously that does not happen with a deformable projectile like an FMJ or the even more yielding hollow point types. But with a solid, non-deforming projectile, it is an accurate representation.
If anyone wants to see the effect of energy per unit area in the equation, you can go back and substitute your favorite bullet's mass, velocity and diameter into the right places and give it a try. A good one to start with is a .45 caliber ACP FMJ (mass=0.015 kg, velocity=250 m/sec, diameter=0.0115 m; quoted Joules = 477).


Gwynedd, thanks for the website. Looks fascinating & I've passed it on for comment. My friend most likely won't look at it because 1) it's too expensive and as a producer he wants to keep costs down, 2) cannot make it large enough for car windscreens, 3) probably cannot be made easily, 4) being more durable, he loses maintainance and rebuild work! He told me that the existing stuff has a usable life of about 1 year as the windscreens delaminate from the sunlight and the cars are worn out from the weight of all the additional armour. Good for a producer.

I was also curious about your energy figures for the different rounds and was going to look at how penetration figures are calculated. I don't normally worry about thing like that as I am a precision shooter and not a hunter. But for Practical Pistol they measure the power factor using the velocity x the weight (but not velocity squared!). Our UK ranges have just been limited by muzzle velocity using momentum (mass x velocity) which acts against blackpowder. According to our Government a .577 black powder rifle is more powerful than a modern 5.56 or 7.62 round!

My penetration queries were started last time I was testing the bullet-resistant glass. My friend had also filled some beakers with his polymer compound, a different beaker for each type he was testing. Without the glass in front we didn't know how far any bullet would penetrate but the best polymer is the one with the least penetration. I was using .357 magnum through a carbine and they all showed less than an inch penetration. I hoped to try more pointy bullets but as we have a poor selection here (if you believe that UK is bad you should try Belfast!) and tried some 124g 9mm heads as they are the pointiest I can find. I have now discovered that 0.001" difference in bore diameter has a great difference on accuracy!

Gwynedd
November 23rd, 2008, 09:31
I take your word for it and Johnny"s for your combined shooting expertise. I'm on the other side of this discipline. I like to stop bullets and I don't really like to launch them.


Hi Johnny,

I was figuring it was a bit more elaborate than that. The process has gotten a bit more refined now from my experience. Instead of fibreglas, some folks use Marine-tex. I prefer Brownell's Acraglas-Steel. It is an epoxy filled with very finely ground stainless steel. I have thought about Devcon Titanium filled epoxy, but not used it yet. The problem is that final processing requires some grinding of the stuff that overflows and Titanium eats normal steel cutters.

Glass bedding for this gun happens in a multi step process. I believe the 5 pillar bedding process developed by Mr. Reid Coffield of Brownells is the best idea but have not used it yet. It basically involves drilling tunnels between the upper bedding areas and the lower through the stock side walls and from the rear horseshoe down to the rear of the trigger assembly and filling with the bedding material. The idea is that wood compresses and bedding material doesn't, so put pillars to take up the compression force.

The stock liner is relieved to allow the legs of the receiver to sit enclosed by bedding material rather than hit the stock liner. Some folks remove the stock liner entirely which I believe is a bad idea because the magazine well then doesn't have a nice steel liner to prevent accidentally chewing up the stock from below.

The Gas system is unitized with the front band and the stock ferrule is polished. The USAMTU process was to anneal the gas cylinder and band and drill through the spindle and cylinder from the back and hold everything in place with a couple hex screws from the back. I have also seen the parts brazed together and tack welded together. I prefer the last two because they leave the gas-cutoff functional. The brazing looks better IMHO. I have also shot guns that did NOT have the gas system modified and did not shoot noticeably worse.

The spring guide is modified either by welding a rod to replace the stamped part that the spring coils over or these days by a piece from Brookfield Precision Tool. The idea is to have a spring guide that is a larger diameter and round so that the spring does not kink up.

The whole gas system is then assembled and gas cylinder lock is then adjusted so that it bottoms out on the threads at 6 o'clock. Shims are used between the barrel shoulder and the gas cylinder to adjust where the lock bottoms out.

The flash suppressor is reamed with a taper so that rain gathering at the bottom will not touch a departing bullet. I have a different idea as to how this should be done, but haven't found anyone to do the machining and welding to test out my theory.

Handguard is held off the barrel with a small rubber washer or piece under the clip. The front of the handguard may be epoxied to the front band. The handguard should NOT touch the barrel or stock in any way. On M14 Heavy barrels, it may be necessary to grind off the underside of the ridges on the handguard to clear the front of the barrel. On standard weight barrel (why would we use these on a target gun???), there will be clearance. On a medium weight barrel, there should also be plenty of clearance.

After initial assembly, there is another adjustment I found in a Marine Corps manual which seems to improve things. The operating rod should bottom out against the gas piston. There will be a small distance (about 3/32 inch) from where the op rod stops and the roller on the bolt. Test this by unscrewing the gas plug. With a .308 Go gauge in the chamber (to substitute for a max size round) check contact distance between op rod and bolt roller. Cut the back of the gas piston until the gas plug only pushes the op rod about 1/32 or less off the back of the bolt roller. This increases the time between when the op rod starts moving and when the bolt starts to unlock. Details regarding testing are too elaborate to describe here.

Unless this is a stainless barrel, you might want to mask off the barrel (without gas cylinder in place) and spray paint the bottom of it with silver engine paint or some heat resistant paint. The idea is to prevent rust from gas fouling from the back side of the gas cylinder. Silver shows up fouling pretty well for those complete disassembly and cleanings.

There are two sizes of NM rear sight aperture. .0520 and .0595. My preference is for the 0.0520. These sights have a notch on the back which indicates the direction of adjustment. Rotating the hood so that the notch goes from top to bottom would lower the sight by 1/2 MOA. The military uses a sight base with finer threads to allow 1/2 MOA adjustments per click. I think these bases have "NM 2/A" markings or something similar. Some commercial manufacturers grind off the detents on the windage knob and put a small cavity in the right side of the receiver under the sight for a spring and ball bearing to index on the notches the cut into the back side of the windage knob. IMHO either one works well enough. Some folks like to cut the lower part of the aperture so that when elevated high enough, the entire aperture comes out of the gun. This is to allow for aperture changes on the range without having to disassemble the entire rear sight. I prefer not to do this.

That's pretty much the process as I remember it. There are a quite a lot of notes on alignment, clearances and checks left out. BTW, for those who might want to actually try this, I accept no responsibility for anything YOU blow up! This is intended as a "War Story". Treat it as such!

- Ivan.

P.S. Remember to cut or grind on the cheaper replaceable part!

Johnny
November 23rd, 2008, 13:24
~S~ G,

First, I support what you are trying 100%. I have had children in the war and now have two, soon to be three grand children in the service. One served in Iraqi.

It never ceases to amaze me how all the laws and values you quoted from Newton and Einstein apply to so many different fields. Like "Joules", especially.

Sir Isaac Newton, 1642 or 3 to 1726 or 7, depending on which History Book you use. He defined laws for things that had not been invented and could not be tested with the instruments available at the time. A very logical person, much like Einstein.

Newton made the laws and the instruments were made later to reflect his laws in the process.

Einstein was not the brightest bulb on the Christmas tree when he was growing up. He went to work in a patten office and started reading this scientific work and it all made sense to him. I really doubt that either could pass the SAT's.

Anyway, "joules", That would be the key that can not be broken and why the robots will be the only solution to the armored vest issue. As I had stated earlier the more the armor is improved the more the weapon is improved.

Make the robots big and strong with lots of armor plating, and make sure the controllers do not become to attached to them.

We (gun people) are thinking bigger is better, but you know in your own mind that smaller is worse. A bullet the size of a tooth pick will shoot holes in any Kevlar you can come up with. The guy on the bike theory in reverse.
.................................................. ..............:bs:
This may well be just another way of avoiding law suites. We are sorry Mrs. Johnson, but we tried to give your son Bobby the best protection possible.

Good luck,

j

Ivan
November 23rd, 2008, 16:41
Hello Gwynedd,

I think I ALMOST understand what you are describing, but there are a couple of minor nits for me to pick at:
There is a misplaced decimal point for 44 mm conversion to meters.
Einstein's E=MC^2 equation really has nothing to do with kinetic energy. It is a representation of the amount of energy contained in matter. The point here isn't how fast the object is going but rather what amount of energy to be released by turning the matter completely into energy. For a Fusion reaction of Hydrogen into Helium, a couple electrons and positrons are annihilated and we get a (bomb or sun) load of energy.

Hi Johnny,

My quest is usually for accuracy and consistency in firearms and taking out the goofies in pretty much conventional firearms. I don't hardly own any guns big enough to brag about.

- Ivan.

Gwynedd
November 23rd, 2008, 18:36
The decimal point point is right. My fingers put things down that my brain didn't say, and then I read them and take them for what I meant.
The Einstein reference is not incorrect. All energy is either mass and motion or force and distance. Physicists are still resolving all the intricacies, but there is no matter that is motionless or massless and none that have no forces associated with them. That it applies to conversion of matter to energy is only a terminal boundary condition of the energy.


Hello Gwynedd,

I think I ALMOST understand what you are describing, but there are a couple of minor nits for me to pick at:
There is a misplaced decimal point for 44 mm conversion to meters.
Einstein's E=MC^2 equation really has nothing to do with kinetic energy. It is a representation of the amount of energy contained in matter. The point here isn't how fast the object is going but rather what amount of energy to be released by turning the matter completely into energy. For a Fusion reaction of Hydrogen into Helium, a couple electrons and positrons are annihilated and we get a (bomb or sun) load of energy.
- Ivan.

Ivan
November 24th, 2008, 05:45
Hi Gwynedd,

I am not disputing your description. I am just disputing that e=mc^2 has a component in the equation that describes kinetic energy.

- Ivan.

Johnny
November 24th, 2008, 09:27
~S~ All,

Energy is the common thread that ran through both equations and if I am not mistaken it is measured in "Joules" and that is why there can be no body armor that works.

"WE (Gun People) ", is a general term for lets say "Rednecks" or "Guys" or whatever. The Bigger the bullet better the weapon. It is a Freud thing. Did not mean You and I.

Later,

J:male:

Ivan
November 24th, 2008, 17:39
Hello Johnny,

There is a big difference between projectiles moving at speeds describable by Newtonian mechanics and stuff moving at relativistic speeds. I thought that we were discussing pure Newtonian stuff until very recently.

I'm not taking offense from anything anyone has posted here. I just may have a slightly different philosophy than you do about sizes of guns. I prefer to use things I can actually afford to shoot. I prefer not to deal with rifles that cost as much in barrel life to shoot as they do in ammunition. I figure to rebarrel a rifle should be around $300 to $500. For simplicity's sake, if the barrel life were less than 500 rounds and each round cost $1, it would cost as much in barrel life as in ammunition. Personally I prefer stuff whose barrel life is measured in thousands of rounds. I also am not fond of getting the stuffing knocked out of me by a heavy rifle. I have shot a .50 Cal Browning that didn't kick all that badly. I have also shot a .338 Winchester that just plain hurt. No fun in that one. With pistols, I try to stay with rounds that I can shoot at least 50-100 rounds without hurting. A full power .44 Magnum is about my limit there. I know a fellow who has a .460 Weatherby Magnum. I don't think he shoots it very much and I am SURE (from personal observation) that he can't hit a thing with it.

- Ivan.

Johnny
November 24th, 2008, 18:56
~S~ Ivan,

I do not reload and never have. I prefer a bolt action .22 mag. rifle and a two shot pistol. One round for two weapons. They are very cost efficient and a good choice as I see it. I have been working on a coil gun lately and the the equations involved are based on the same Newtonian laws, but the "Joules" are the common thread that runs through Newton and Einstein's theories.

The energy is caused by gun power vaporising at enormous rates forcing the projectile out of the confined space, (chamber/shell casing) and out the barrel of the weapon. Bolt action weapons are slightly better then automatic weapons but the recoil is greater. You reload shells, do you use stick or powder?

In coil guns the excellent magnetic energy. Electricity, thousands of volts, creates a magnetic field and the projectile is drawn to the center of the field. The field has collapsed before the projectile can reach the center. As the projectile passes it trigger a second field farther down the barrel and the speed is jumped, because it is no longer at rest and is now in motion. This can be repeated to the point that one of two things can happen. It vaporizes (I doubt I could do that, but it could happen), or it reaches the speed of light (do not believe that either). Most believe it could go nuclear. "Supper Collider" E=MC^2

Newton to Einstein.

My gun will not be that long.

j

Ivan
November 25th, 2008, 09:32
Hello Johnny,

I have a friend at the Collider / Detector Facility (CDF) at Fermilab in Chicago. She gave me a pretty good tour and explanation of how things worked. Their setup is about 4-6 miles in circumference under a canal for cooling and can accelerate particles to a very high portion of the speed of light. They collide particles in the hope of creating temporary subatomic particles that may exist only for very short times.

Yes, energy can be measured in Joules, but sometimes kilowatts is a more apropriate unit.

Somehow I don't think your setup is going to be capable of that, but really high speed (several thousand fps) projectiles are still interesting.

A .22 Magnum is a pretty odd cartridge selection. I don't see those as being particularly inexpensive though.

Regarding reloading, I use a variety of smokeless propellants:
Stick Powders:
IMR 3031
IMR 4064
IMR 4895

Spherical Powders:
Winchester 748
Winchester 231
Winchester 296

Flat Disc / Cylinder Powders:
Alliant BlueDot
Alliant 2400
Alliant Unique

For Black powder, I usta use a fair amount of FFFg and FFg. I don't think I have any more of either. This list doesn't cover all of the stuff I have used, but is a pretty good representation.

- Ivan.

Gwynedd
November 25th, 2008, 21:32
I really hate to do this "I'm right, you're wrong" thing. It always creates hurt feelings, and I try to avoid that.
May I please just refer you to a well constructed debate on this subject among an anonymous contributor, a PhD candidate at MIT and a PhD research scientist?
http://www.physlink.com/Education/askExperts/ae121.cfm
I will let you draw your own conclusions about whether a kinetic energy reference is appropriate.


Hi Gwynedd,

I am not disputing your description. I am just disputing that e=mc^2 has a component in the equation that describes kinetic energy.

- Ivan.

It has been a long, difficult 5 day work week yesterday and today. Everything had to get done before the holidays were here. I'm pretty tired, so Happy Thanksgiving everyone. See you later.

Ivan
November 26th, 2008, 06:01
Hello Gwynedd,

As far as I am concerned, I don't take offense at the "I'm right, You're wrong" thing. Thanks for the reference.

Let me state for the record: If I understand the discussion correctly:
Gwynedd is right and I'm wrong!

Please correct if my interpretation is incorrect here: The mass in this equation is not a constant. It changes as to the velocity of the object. The change does not become significant until relativistic speeds are reached, but is enough to account for the increase in kinetic energy normally calculated in the Newtonian world as 1/2*m*v^2.

Happy Thanksgiving!
- Ivan.

Gwynedd
November 26th, 2008, 06:46
Ivan,
Yes that is exactly what it means. And thanks. I was dreading looking confrontational about this. I really just your typical teacher type.
In fact I am such a nerd that I watched hours of History Channel's The Universe last night while getting things ready for Thanksgiving. It was mostly about topics related to this.
Now I just need someone to explain to me about muons. They are sub-atomic particles that only travel faster than light and have to slow down to reach light speed. According to the Lorentz equation, time becomes an imaginary number for them :jawdrop:

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/tdil.html


Hello Gwynedd,

As far as I am concerned, I don't take offense at the "I'm right, You're wrong" thing. Thanks for the reference.

Let me state for the record: If I understand the discussion correctly:
Gwynedd is right and I'm wrong!

Please correct if my interpretation is incorrect here: The mass in this equation is not a constant. It changes as to the velocity of the object. The change does not become significant until relativistic speeds are reached, but is enough to account for the increase in kinetic energy normally calculated in the Newtonian world as 1/2*m*v^2.

Happy Thanksgiving!
- Ivan.

Gwynedd
November 26th, 2008, 08:05
Happy, safe, loving and memorable Thanksgiving to you and everyone here.
To those whose nation doesn't celebrate Thanksgiving or celebrates it at a different time, celebrate with us too!

Gwyn



Hello Gwynedd,

Happy Thanksgiving!
- Ivan.

smilo
November 26th, 2008, 10:17
well said Gwynedd.
Happy Thanksgiving Everyone

Johnny
November 26th, 2008, 13:18
~S~ G,

I know all about morons, I is one.

Happy Thanks giving all.

J:isadizzy: