WW2 British .303 guns-just boring trivia.

[Ignition Override]

Hello over there: just finished playing the UbiSoft 'Pacific Fighters' (Quick Combat).

I have only flown transports, but enjoy this amazingly graphic computer game and always am curious about machine gun bullets and 23 or 37 mm cannon rounds.

Also have the dvd "Battle of Britain", was just thinking about it and suddenly a question came to mind.

Despite the fact that the Spitfires and under-appreciated Hurricanes had either six or eight guns per plane, were the shells a good bit longer with much more gunpowder than those loaded into the Lee-Enfield rifles? Curious about the impact force of "rifle-caliber" bullets, and could not picture about six or so rifles, even if flown at high speed, able to tear into the wing tanks or engines on a Ju-88, Do-17, Me-110 or He-111 with much damage caused. But maybe many rounds had incendiaries?


Have seen gun-camera footage from a P-47 firing at ground targets-the impacts of those eight 50 caliber bullets in one small area looks like a serious explosion, despite the grainy old black and white film .
:eek:

[StopStart]

Second article down in a google search.....

Spitfire 303 rounds (http://www.quarry.nildram.co.uk/BoB.htm)

[GeeRam]

Despite the fact that the Spitfires and under-appreciated Hurricanes had either six or eight guns per plane, were the shells a good bit longer with much more gunpowder than those loaded into the Lee-Enfield rifles? Was wondering about the impact force of "rifle-caliber" bullets, and could not picture about six or so rifles, even if flown at high speed, able to tear into the wing tanks or engines on a Ju-88, Do-17, Me-110 or He-111 with much damage caused. But maybe many rounds had incendiaries?

Hurricanes and Spitfires were both equipped with 8 x .303 Brownings during the Battle of Britain, although a tiny handful of experimental cannon armed Spitfires did see combat in the latter stages of the Battle.

The ammunition used for these Colt manufactured Browning MG’s was identical to the standard issue .303 ammo used in the Lee-Enfield rifles, Bren and Lewis LMG’s and Vickers MG’s.

[Ignition Override]

Those pilots did a spectacular job, especially as most seem to have been quite low on operational experience, even when the war broke out.

[TwoDeadDogs]

Hi there
With regard to the .0303s and other guns;just a few points.
The .303 round fired in the aircraft used some DeWilde incendiary rounds,which were not used in ground-fired weapons.Some .303 rounds are not interchangeable between firearms,eg; the Lee Enfield used a .303 ball round which could be fired in the Bren but had a lower powder charge than the official Bren round,the Ball Mk VIIZ,which could not physically be loaded into the Enfield rifle,because the cartridge was slightly different. Also, it was a fact that many German bombers limped home,despite having been riddled with .303. The weight of fire is what really matters and the German combination of 7.92 (fired at a faster rate than the British guns) and the 20mm Oerlikon shells was much more effective. Rifle-calibre bullets punch small holes in aircraft and often fail to penetrate even light armour or destroy system piping, structures and engines,whereas it takes very few cannon rounds to wreck an aircraft. Quite why the designers didn't go for the Browning 0.5-inch,even when the Belgians were using them in their Hurricanes,is beyond me. The fact that the Germans had a working cannon arrangement, along with the French, is a black mark against the British designers,for not having such for their pilots. Conversely, all sides were guilty of allowing their bombers to go out against their enemies,with only rifle-calibre guns,often in single mounts particularly the Blenheim, the early Ju88,etc.
regards
TDD

[Farmer 1]

It needed many more hits with bullets to shoot down an aircraft than it did with cannon shells. I believe cannon eventually replaced the machine guns, at least on the Spitfire.

An excellent reference book on these aircraft, and those on the other side, is "Fighter", by Len Deighton.

[BEagle]

And the Hunter's 4 x 30mm Aden cannons put more bang into the target than the Phantom's much-vaunted 20mm Vulcan cannon fired for the same length of time!

It must be true - a QWI told me!

[pulse1]

I understand that Douglas Bader was very much against the use of cannon during the BoB. He reckoned that it would encourage pilots to shoot from longer range, and miss, instead of getting in close as you had to with the Brownings.

[Onan the Clumsy]

That article only briefly mentions harmonisation.

Eight guns you may have and cannons not, but if they are all directed to the same point in space, then their efficiency is improved dramatically

[PA-28]

I think you'll find that the 303 VIIz is dimensionally identical to the conventional ball rounds, fitting Lee Enfield, BREN etc. it WAS a higher power loading and marked ( with a black tip, and painted primer canneleur ? from memory ) not for use in the No 4 etc, an ‘Air service’ round and commonly used in the water cooled Vickers, along with the later VIIIz, an indirect fire round.

I wouldn’t dismiss these rifle calibre rounds too casually, remember eight of them, at 1200 rpm each, especially with the guns synchronized to 250 – 300 yds, the concentration of fire at closer ranges would do an awful lot of damage.


PA-28

[Climebear]

Quite why the designers didn't go for the Browning 0.5-inch,even when the Belgians were using them in their Hurricanes,is beyond me.

Quite possibly the same reasons as the fact that the USMC's Harriers have working guns whereas UK PLC's GR Harriers do not!

[tucumseh]

"Quite why the designers didn't go for the Browning 0.5-inch,even when the Belgians were using them in their Hurricanes,is beyond me".


Good point. And quite why the UK never went for his designs until long after he died (1926 I think) is one of life's enduring mysteries. Even then, it was almost by default due to his long association with Fabrique Nationale des Armes de Guerre (have I got that right?). Having said that, most 20th century small arms work on his principle of delayed blowback. Everything else is cosmetics/ergonomics. I read once that the US Army trials plan for their "LMG" in the early 1900s called for a 10,000 round demo and they would assess stoppages. Browning himself spent a day firing over 20,000 rounds from one BAR, then in darkness field-stripped it, cleaned it, assembled it and carried on firing. No stoppages. (A hundred years later, can the SA80/LSW do that?). The Bren was good (30 years later), but the first thing you had to master was the Immediate Action due to continuous stoppages. (Gun stops, cock gun, mag off etc). The only criticism of any of his designs was the "Hi-Power 9mm" (around 1924 when he was getting on a bit) and still in service in the UK. The double action was and still is "an ingenious solution to a non-existent problem". But he was an engineer, not a soldier. And a very fine one.

[Farmer 1]

justapplhere

Yes, that is correct.

[maxburner]

But Beagle, the Phantom's gun made such a wonderful noise, from inside the cockpit or on the ground in the RSO's hut. Sheer magic. Like a mystical dragon farting!

[Sloppy Link]

PA-28
Interested to know where you get a cyclic rate of 1200rpm, I suspect that to be a bit generous. Current day GPMG (piston operated) is 650-900 dependendant on gas regulator setting with an optimum of 750 rpm. The main limitation is the spring being able to fully compress under the the effect of the gasses far enough rearwards to eject the spent round and exert itself again with enough force to collect the next round to feed into the breech and strike the firing pin hard enough to cause the round to expend. This is especially prevelant using a delayed action blowback theory as I understand the .303 Browning to be. Curent Rifle and LSW (locking spline piston delayed blowback) also is around the 750rpm figure and even mechanical (chain) gun is still around the 625 rpm (Apache, although I fully realise that 30mm ammunition is far harder to shift around). To increase the cyclic rate, you would need to introduce more barrels (Dillon mini-gun M134) or start getting really clever with caseless rounds and computer generated firing sequences.
What I do not know is this.....When a BoB Pilot operated the trigger, did all 6/8 guns fire at the same time or was there a delay in the electrical circuit introduced to each gun. If this was the case, a collective cyclic rate of all 6/8 guns of 1200rpm would be believable. As has been said before, the collective effect of lots of .303 is greater than the single effect of a higher calibre weapon. I am sure a very clever man in the Wartime RAF mathematically proved this.

[Ignition Override]

Thanks a bunch for the info. I saw a wonderful comparison, (on the US "History Channel"?) using a static test, whereby several rounds fired from a Spitfire-type .303 into whatever fuselage, then a few shells from a cannon of an Me-109. The .303s might have been fired as single shots, and this must have been unrealistic, but because of the very slow rate, there was no comparison, unless, as stated by you all, the multiple .303 rounds at a normal rate of fire converged at the right distance. The purpose was to check results up close with the television camera, and the film quality was good.

Hell, as for shooting REAL guns, nowadays, so much land has been bought up around this city and the countryside (real estate speculators), that there is no place outside where you can shoot a basic .22 rifle at a cantaloupe or orange floating down a small river :mad: . Inside rifle ranges, we can choose between various, exciting, paper targets (but can rent a few pistols in there, and cheap) :8 .

Some Soviet rounds (23mm?) were fired, on a very different program, from whatever type of ground or aircraft gun at a 90 degree angle into the outside skin, just below the canopy of a Soviet Su-25 "Frogfoot". What a superb flying machine! The rounds were fired from about 20 feet away, and possibly due to the armour around the c0ckp1t, the bursts looked something like a very tiny paper bag of flour thrown against a brick wall. I wish we could drop some (lots) inflight :E. I could not see from the faded old Soviet film that there were any metal fragments.

[The Nr Fairy]

Bee Beaumont's autobiography "Flying to the limits" contains a discussion of the effects of harmonisation.

Would it surprise modern front line pilots to learn that, even in WW2, ministry folks / theorists thought that adjusting the machine gun pattern to spread rounds across a large area was more effective than that proven by the pilots, which was to harmonise on a point in space and thereby improve the chances of a kill ?

[Argonautical]

Quote - "The Hi-Power 9mm" (around 1924 when he was getting on a bit) and still in service in the UK. The double action was and still is "an ingenious solution to a non-existent problem"
-----------------------------------------------------
The Browning Hi-Power, as issued during the war, is not double-action. First round must be cocked then all the rest are automatic.

FN much later, around the 80's I think, did revamp it to double-action but I don't think it was a commercial success.

[PA-28]

Sloppy Link :-

I’ve had a chance to check up on some sources , including Len Deightons excellent ‘Fighter’, it looks like 1200 per minute per gun is correct, which as you point out is a fair bit higher than the 160 rps(econd) quoted in the earlier link in this thread. Guns optimised for the air combat role will not necessarily mimic those for the ground combat role, The .303 Browning M2 was hoping to put as many rounds into a target in the shortest possible time, the manual deflection shooting required at the time being a skill of the highest order. 300 rounds per gun also must have meant there would have been little chance to ‘walk’ tracer onto a target, a series of short , in fact very short bursts., with only 15 seconds of fire engaging four of five targets, and shooting them down, on a single sortie must have been close to the then prevailing limits. Hence the move to cannon rounds, if a single projectile could bring down the target , by virtue of its explosive capability then the attractions would have been obvious. Having said that 20 mm (Hispano and Oerliken) seems to be about as small a calibre as ammunition manufacturing can produce a viable explosive cannon round, and reliability issues plagued the early cannon deployments.

I’m sure all guns fired simultaneously, this link to a copy of the Pilots Notes Spitfire IIA details no selector switches, although I believe there were ammunition gauges provided per gun.

http://www.zenoswarbirdvideos.com/Images/spit/Spit2Manual.pdf

Just to set things straight the .303 vii and viiz loadings were standard issue across all weapons including No 4 BREN etc., although you probably wouldn’t want to run it through a Lee Metford too often.

Clearly by the end of hostilities the Allied armaments industry wasn’t entirely satisfied with the performance of the Hispanos etc, the post war development of the Mauser MG213C revolver cannon design lead to the ADEN / DEFA series, and a move to 30 mm calibre yields a much more effective terminal effect. The introduction of radar gun laying and HUDs allow much more accurate placement of the relatively heavier and potentially slower moving projectiles. If you compare the case capacities of the 30mm ADEN and the ‘milk bottle’ rounds from the GAU-8 you can clearly see which designer was going for armour piercing effect, velocity squared, 750 m/s against 1000+ m/s. ( Having said that a 303 is ‘only’ 750 m/s)

Nerd mode off.

[uncivilservant]

Just to clarify the different marks of .303 ammunition. PA28 is correct, Mk VII and Mk VIIz were interchangeable, the difference between them was that the former was loaded with cordite as a propellant, the latter with a nitrocellulose-based powder (which is what the "z" suffix means). During WW2, most British-manufactured ammo was Mk VII, the USA supplied Mk VIIz which was issued to the RAF (amongst others). The Mk VIIIz was a special long-range round for the Vickers MMG. It was no more "powerful" than the MkVII, but had a boat-tailed bullet which had superior ballistic performance - giving an effective range of over 4,000 yards. Mk VIIIz can be used in rifles, and in fact some of the surplus ammo available in the UK not long ago was Yugoslavian MkVIIIz. I have never put any through a rifle, but did have the privilege of putting 100 rounds of it through a Vickers in 2002.

As for Spitfire/Hurricane armament - I thought the cyclic rate was nearer 1000 per min, which was not uncommon for an a/c gun; the Vickers K observers' gun had a cyclic rate of 1050. The decision to equip fighters with 8 guns was arrived at based on a mixture of assumptions and simple mathematics. It was estimated in the 1930s that with the speed of modern aircraft a fighter would only be able to hold an enemy aircraft in its sights for a couple of seconds (I forget the exact figure). It had been calculated that it would take a certain number of bullets to cause fatal damage to a bomber. Using these numbers plus the known rate of fire of the gun it was possible to calculate the number of guns that would be required for fighters to shoot down bombers.

OK, I'll put away my anorak now.

[Green Flash]

Funny. I've just been reading a book on DB and his dislike of cannons. When his squadron were re-equiped with Spits they all got the Mk Vb, with cannons. DB got a strop on so they gave him a Va - just machine guns. He had a few arguments with 'Crow' (Crowling-Milling) but it seems that his objection to cannons was one of the few times he was wrong.

[Farmer 1]

Yet more even more boring trivia: I believe the expression "The full nine yards" has something to do with the length of the .303 ammunition belt.

[Pontius Navigator]

Beags was right:


And the Hunter's 4 x 30mm Aden cannons put more bang into the target than the Phantom's much-vaunted 20mm Vulcan cannon fired for the same length of time!

Just found the AP.

An Aden had a rate of fire of 1200-1600 rpm whereas the SUU was set at 4000 or 6000.

4xAden therefore were delivering between 4800 and 6400 rpm with each shell weighing in at 10 oz.

The weight of the 20 mm is clearly much less.

[TyroPicard]

The whole nine yards...

I was told this referred to the B-17 waist gun, which had a 9-yard ammo belt. Normally the gunners would save 2 yards for the homeward journey, but if things looked bad they would ask the Captain' permission to fire "the whole nine yards"... Can anyone confirm, or produce a better story?

TP

[Farmer 1]

TyroPicard,

You never know, one of us might be right. Your story sounds at least as reasonable as mine, except I would have thought the Yanks might have been able to afford more than nine yards, especially with all that space available in the aircraft.

So, how many rounds in nine yards? I've no idea, and no intention of trying to find out. Anyway, if you knew that, and the rate of fire, you could work out how long the belt would last. I suspect not very long, and I have seen film of B-17 gunners ankle deep in empty cases. They obviously had a need to maintain fire for extended periods, not just ten seconds or so.

Also, how would the gunner know that there was only two yards of belt remaining?

However, I have been wrong once before.

Farmer.

[Danza]

On a slight Hijack. Has anyone seen the program on the recovery or the P-38 from under the ice. They mounted one of the canons onto a snowmobile, bore sighted it onto an empty oil drum and fired one shot .... it virtually blew the barrel in half!

[Centralize]

Uncivil Servant - Where can you fire a Vickers in this day an age? I want a go! Pers message me if required

Ta

[MightyGem]

The Whole Nine Yards (http://www.yaelf.com/nineyards.shtml)

[Farmer 1]

Interestinger and interestinger.

I still plump for the Spitfire angle. But both this and the B17 gunner option should be the easiest to disprove, at least. There are still many of those gallant chaps around. Some of you will know them - could you ask them, please? If the phrase was in common usage, it would surely feature in the odd battle report.

If none of the men directly involved can remember it, then I would think that would be proof enough that it has nothing to do with machinegun belts.

[Onan the Clumsy]

Nine cubic yards in a concrete truck.

[PA-28]

'The Whole Nine Yards'



Centre to centre the disintegrating link for the .30-06 Browning measures about 12mm. This gun, re-chambered for .303 British was the M2 used in the Spitfire etc. The belt pitch may well have been slightly wider, to accommodate the rimmed cartridge, but not massively so. So at 300 rounds per gun, we have 3.6 meters / 11 Ft 9 3/4 in. Way short of the 9 Yards / 27 ft.

That tends to limit the discussion to turreted weapons with belt feeds, looking at the figures a thousand round belt of some other ammunition, slightly narrower would fit the numbers, and belt make up would have been done with bulk supplied rounds to a standard length. I always sort of assumed that the phrase was American, so I would have expected .30-06, can anyone do a check on .50, maybe a 500 round belt.

PA-28

[Ignition Override]

Danza: the show I saw might have been another, or found the program partly over.

But I was fortunate enough to see the first flight of the P-38 (known to the Luftwaffe as the 'fork-tailed devil', 'Gabelschwanz Teufel'), nicknamed 'Glacier Girl' on tv, where a well-known pilot who races WW2 planes took it up for a short test flight. The thousands of hours spent in renovation alone are mind-boggling. The flight was in upstate New York, in front of a large crowd of fans.:D

To fly the ( twin-engine) Mosquito would be just as exciting.

[Pureteenlard]

Since a hot debate is going on on another forum which intersects with this .303 thread I thought I'd share this quote with you (the 'myself' mentioned is Anthony Williams, Co-author of 'flying guns' which I can highly recommend);

"On the contrary, rifle-calibre bullets were already proving themselves to be inadequate in dealing with the new, tougher structures required for the fast monoplanes - even without armour. The extract below, from 'Flying Guns – World War 2: Development of Aircraft Guns, Ammunition and Installations 1933-45' by Emmanuel and myself, describes the results of British tests of .303 and 7.92mm armour-piercing ammunition on a Blenheim - scarcely the most strongly-built of aircraft:

"The test then changed to shooting at the rear of the long-suffering Bristol Blenheim at the same distance [200 yards], involving penetrating the rear fuselage before reaching the 4 mm armour plate protecting the rear gunner, which was angled at 60º to the line of fire. The results in this case were reversed; 33% of the .303" rounds reached the armour and 6% penetrated it. In contrast, only 23% of the 7.92 mm bullets reached the armour, and just 1% penetrated. The British speculated that the degree of stability of the bullets (determined by the bullet design and the gun's rifling) might have accounted for these differences."

Please note that only a third of the British AP bullets - and less than a quarter of the German ones - reached the armour at all; the rest were deflected or absorbed by the structure. That no doubt accounts for the German bombers which reached base despite being riddled with .303-shaped holes.

It's interesting just how much the penetration was reduced by passage through the light alloy of the Blenhiems fuselage. A move to the 20mm Hispano was definitely a Good Thing!