Tracers in period 1940-42

[mongoose]

Thinking of the Spitfire MkII and the fact that tracers were apparently not used; excepting for the last few rounds(?), is there any more information on the use of tracers, including the change in use of them for :-

RAF - all day fighters
- Night Fighters
- Bombers

LW - the same. plus the fact cannons were more common.


So if BoB RAF ac did not use them, can the Spitfire MkII weapons loads be transferred to other period ac and if so, which files need amending? I will look myself as well but to save time.....

[mongoose]

So far this is all I have found which is not very definitive IMO.

Bomber Command Ammuition 0.303-in.
Between January 1942 and May 1944 the operational sequence for belting
0.303-in. ammunition was as follows:

7 A.P., 2 incend., 1 tracer (day or night)

On the 26th May 1944, provision was made to alter the current sequence, should the necessity arise, to enable a quick turn-round of aircraft for day/night operations, to be effectec:

Rear Top left: all 70% A.P., 30% Incend., no Tracer
Top right: 1st 500 rounds like above
Reminder 50% A.P., 20% Incend., 30% Tracer (Night)

Bottom left: All 60% A.P., 20% Incend., 20% Tracer (Night)
Bottom right: All like above

Mid-Upper and front: Both 1st 300 rounds, 60% A.P., 20% Incend.,
20% Tracer (Night)
Reminder 60% A.P., 20% Incend. 20% Tracer (Day).

===============================
Part two:

Night Operations:
In the event of more than 300 rounds being fired from each gun of the rear turret, the top right-hand gun was made "safe" leaving three guns available for combat. It was considered that under reasonably light conditions, the small percentage of day tracer would not interfere with sightning, in which case the top right-hand gun could have been used. It was considered unlikley tha more than 300 rounds per gun would be fired from the mid-upper or front turrets.

Day Operations:
The 300 rounds of night ammunition in the top right-hand gun ammunitions tracks were removed befor the guns were used operationally. The first 300 rounds of each belt in the mid-upper and front turrets were removed and the tanks replenished with daylight sequence before the turrets were used.

Tracer Ammunition:
The points infavour of the discontinuance of the use of tracer were summarised as follwos:
a). The very reald danger of the gunner "hosepiping" tracer in the direction (approximate) of the fighter, disregarding this sight altogether.

b). In view of the adoption on the zone method of sighting, tracer ammuntion only served to indicate line accuracy. In the corkscrew this value was lost.

c.) It was considered that the use of tracer ammunition was so distracting, that with qyro gunsight Mark IIC, the gunner could not properly track a target with the moving graticule.

=====================================
Part three:

Bomber Command planes with 0.50-in Ammunition:
By No. 2 Group from 18th September 1942 onwards:
40% A.P., 40% Incend., 20 % Tracer

From:

17th January 1944: 3 A.P.I., 1 incend., 1 night-tracer

10th February 1944: 1 A.P.I., 2 A.P., 1 incend., 1 night-tracer

29th January 1945: 4 A.P.I., 1 night-tracer

30th April 1945: 100% A.P.I.

===========================

After a combat of 7th August 1941, Kingaby (92 Sq, Spitfire Mk.Vb) commented that his ammunition had included no tracer, and if they had the results would have been much more positive.

====================
Tony Williams


also see also see http://www.quarryhs.co.uk/BoB.htm


From my book ‘Flying Guns: World War 2’:

The RAF fighters armed with eight .303" guns differed from the usual practice by loading each gun with only one type of ammunition. During the Battle of Britain in 1940, the reported use was three guns loaded with ball, two with AP, two with Mk IV incendiary tracer and one with Mk VI incendiary (the “De Wilde”). It is not clear why the Mk VI was used so little or why ball was used at all; possibly there was a shortage of the more effective loadings.

RAF Bomber Command principally used .303" guns for defensive fire. In 1942 the approved ratios for loading the belts in four-gun turrets were 65% AP, 25% incendiary and 10% tracer (two-gun turrets had 20% tracer with the others reduced accordingly). Between 1942 and 1944 the approved sequence was 70% AP, 20% incendiary and 10% tracer. This was modified in May 1944 to increase the proportion of incendiary to 20-30%, and changed again just before the end of the war to 100% incendiary, on the grounds that the German fighters were too heavily armoured for rifle-calibre AP to have any effect, whereas incendiaries at least stood a chance of setting light to something. Fixed .303" guns for air fighting were loaded 50% AP and 50% incendiary; for attacking ground targets the figures changes to 75% AP, 25% incendiary. The .303" Mosquito FB nose guns were loaded with unmixed belts of AP and incendiary rounds; i.e. two guns fired only AP, two only incendiaries (this also appeared to be standard practice with Spitfire .303s).




and

An extract from 'Flying Guns: World War 2':

"There was a considerable debate (which continues to this day) about the desirability of tracer ammunition. It was generally felt to be useful in bomber defensive weapons as the sight of tracers curving towards them was observed to distract attacking fighter pilots. In fact, the USAAF even used a tracer round for bomber defence, the M21 "Headlight," which was specially developed to be as visible as possible from the front for exactly this reason. On the other hand, Air Marshal Harris disapproved of RAF gunners using tracers as he felt that this encouraged them to "hose" the target instead of using their sights. In night bombing, some crews were cautious about firing as tracers merely gave away their position; so were their opponents. The Luftwaffe used Leuchtspur during the day (L'spur) but Glimmspur (dim trace) at night. Upward-firing guns in Nachtjäger (night-fighters) usually used no tracer at all, although some pilots liked to include some Glimmspur.

There was also a debate about the use of tracers in fighter aircraft. Some argued that tracers were useful in correcting their aim, or even in firing to one side of enemy aircraft to persuade them to change course (which sounds suspiciously like a theoretical concept; if enemy aircraft were in range, most fighter pilots would sensibly be shooting straight at them). The counter-argument is that the sight of tracers flashing past them gave enemy aircraft instant warning of attack and enabled them to take prompt evasive action. It has been reported that USAAF fighter units in Europe which did not use tracers scored considerably more successes, and suffered fewer losses, than those which did, which would seem to settle the argument. On the other hand, tracers could help the pilot in ground attack or in judging any sideways drift.

One general problem with tracers was the impossibility of matching the trajectory of other ammunition types, because of two conflicting factors. First, projectile weight was usually lighter than standard, and reduced as the tracer element was burnt up anyway; also the gas generated by the tracer burn reduced the pressure differential between the front and back of the projectile and therefore reduced drag. Tracers were generally specified to match the aiming point of other ammunition at some specified distance and remain within set tolerances at other distances. Another problem in explosive cannon ammunition was that the tracer used up some of the shell volume and thus reduced the space available for HE."

==========================

[gecko]

My detailed knowledge extends only as far as RAF fighters at this point. RAF practice was to load only a single type of ammunition into each gun, instead of having mixed belts as was common elsewhere. Different guns would be loaded with different types of ammunition on the same plane however, achieving the same result. Typically, for a Spitfire or Hurricane, the outboard most pair of guns would be loaded with some kind of indicator round.

Early war and phasing out during the BoB, but still very much in use during that time if you look at the existing gun camera footage, phosphorus smoke tracers were used as the indicator round. From the Spitfire package, use SJ_gb_gun_303cal_INCT, and SJ_gb_gun_303cal_INCT2 (the 2 or 3 at the end of some of the gun files signifies using a slightly different gun sound to provide a fuller sound of multiple guns when used in combination with the others). Make sure you specify Tracer="100" for these guns in the aircraft's xdp.

Starting during the BoB, but still in limited use initially due to limited stocks, the De Wilde incendiary began to be used. There was no tracer, but instead a bright flash on impact with the target, letting the pilot know he was hitting his target. This was considered more useful than a tracer, since the tracer trajectory was different from the rest of the rounds anyways. Now the pilot could clearly see if his rounds were actually hitting the target. De Wilde would eventually replace the phosphorus tracers in the outboard guns, but early on while supplies were limited, the outboard guns would still use phosphorus tracers and one of the other guns would be loaded with De Wilde incendiary. From the Spitfire package, use SJ_gb_gun_303cal_INC, SJ_gb_gun_303cal_INC2 or SJ_gb_gun_303cal_INC3.

The other guns would use either AP or ball ammunition some loaded with one, and some loaded with the other. These had no tracer nor any discernible indication of a hit when impacting an aircraft. From the Spitfire package, use SJ_gb_gun_303cal_AP, SJ_gb_gun_303cal_AP2, SJ_gb_gun_303cal_BALL, or SJ_gb_gun_303cal_BALL2.

Another note, the "_gun_trigger" suffix will have that gun be fired using the gun button, and those without will be fired by the cannons button.

As far as I know, the RAF never used tracers with 20mm ammunition.

I believe RAF gunners used mixed belts with colored tracers (red?) AP, and ball ammunition. I don't know this for certain though.

I would expect RAF night fighters not to use tracers either, but I really don't know.

For the Luftwaffe, I think mixed belts with AP, and red or white tracers were standard for the 7.92mm guns. I believe the 20mm MG FF used a mix of yellow tracer and HE. The later 20mm MG FF/M ammunition could not accommodate a tracer, so it was all HE.

[mongoose]

Dan. I think our posts crossed! In any case can I use your Spit loadout for other Spits (Mk I's) Hurricanes, and if so, what files should I use and I suppose the xdp's have to be altered.

[gecko]

I've listed the required guns from the package in the post. Enter those into your Hurricane's edp in place of whatever guns are there. Just make sure you have the contents of the guns and weapons folders from the Spitfire package (and the lines for the effects and sounds xmls) installed.

[mongoose]

Ooops! Noted! I'll give those a go later.

[NachtPiloten]

D Been reading "The Blitz" and the British reports speak to tracers and the de Wilde ammo. So it appears that there was a mix of use even in early 1941.