20mm cannon, best, worst, specs, comparison to LMG, HMG etc.

[post76]

If the Russians truly pulled the wing .30s from the early P-40s they must have been really desperate

They may have removed them but after reviewing lend lease shipments, many P-40s were shipped with out them installed in the first place.
I loosely did some math based on the gun weight and ammo and it would've cut about 175lbs off the weight of the plane if their were two guns per wing and a total of 500 rounds. I'm not sure how much the gun mounts weighed but that would probably bring the total closer to 200-225lbs.
I thought maybe the RAF had picked/pulled them for their Spitfires but US shipments directly to Russia show no .30s included.
This may have been at the request of the Russian military to lower work load, but i would think the .30s would still be useful in action if not on the airplane.
Another reason for pulling them may have been a lack of ammo that matched or adequate serviceability??
I also wonder if the Russians replaced Browning 50s with their own cannons or 50 caliber guns for serviceability reasons.
I only pose the question, i'm not making the claim.
I know they limited engine outputs on lend lease aircraft for the same serviceability reasons.
Ie, having to tare down/rebuild after 120 hours vs after 50 hours. and something about poor oil quality.

such guns were a really bad armament in 1940 against such aircraft as as a Do 17 which was only about 20% heavier than a P-47 empty and a much bigger target doesn't follow

Larger aircraft frames tend to absorb more gunfire if not because they are more resistant, because they are larger targets. Pilots and engine parts or no less vulnerable.
Wing area is another point. A plane sprays another plane with gunfire could be cannons, doesn't matter, and causes a total of 4 square feet of holes in the wing area. This would be a less percentage of wing area on a larger plane than one on a small fighter.

I still hold by the fact that wing radiators were particularly easy targets for 303/30 loaded planes and they may not have been the best weapon beyond that capacity but still effective at closer range.
Furthermore, P-47s didn't have wing radiators, and neither did most bombers. Its no wonder it took most of their ammo loads to inflict any meaningful damage and i refer to discussions of the BoB where Doniers were found returning home with thousands of holes.

If you are familiar with Johnsons story, what had originally knocked him and his formation out of the sky was a burst of 20mm fire which, imo, did inflict heavy damage, igniting a fire and destroying the throttle quadrant injuring Johnson in the process. He recovered in the dive and was bounced again by the same 190 (if that is an accurate account) who then unloaded with his LMGs at low speed.

 

[pinsog]

2 popguns did often bring down early war aircraft. Not often enough it is true, but if two "popguns" could do the job a fair amount of the time trying to claim that 8 such popguns were a huge mistake doesn't make much sense.
The Bf 109 fought in Poland and France with , at times, four "popguns" and the rest of the time with two 20mm guns very close to the Japanese Zero and two "popguns" firing through the prop. They kept the two "popguns" for another 2 years. Mostly because they didn't have anything better. Same situation as the Zero, 20mms are empty in about 8 seconds and any additional fighting is done with the "popguns".






Something of a mixed message here. the 240 rounds per gun for the F4F-4 weighed 532lbs. that is just the ammo. you are comparing the ammo for a single gun to the ammo for two cowl guns. Are you saying that single .50cal MG would have done any better in the situations you describe than the paired "popguns" with their much higher rate of fire and much higher hit rate?


Bad analogy's, you don't "spray" an elephant (or even spray the area it is in which is what some air combat came down to) with gunfire and hope to hit a vital part. your tank analogy might be better if compared a Sherman with a 75 to a Sherman with a 17pdr. and even then it depends on the target.


Ah yes, two famous incidents that do not tell us how many times Japanese or German pilots used the same tactic and succeed in shooting down the target. Now going back to the Wildcat, there is little doubt that with either four or six .50cal guns they would have made short work of the target but let's examine the Johnson case a little more closely. Why was the German pilot using his "popguns"? to save 20mm ammo or had he used up all his 20mm ammo already? Fw 190s carried 200rpg for their wing root 20mm guns that fired a bit slower than .50 cal mgs. Any fighter armed with .50s with 200-240rpg would have been out of ammo and in no position to attack Johnson with any gunfire.
Now by 1943 the "popguns" had certainly seen their day and carting around a pair of them with the ridiculous amount of 1000rpg ( around 35-40 seconds more firing time than the 20mm guns) seems a bit of a waste, but claiming that a pair of guns that guns that couldn't bring down a P-47 in 1943 means that eight such guns were a really bad armament in 1940 against such aircraft as as a Do 17 which was only about 20% heavier than a P-47 empty and a much bigger target doesn't follow.

You misunderstood me reguarding the Wildcat, I meant if Saburo Sakai had a pair of syncronized 50's, he could have destroyed the Wildcat without resorting to using his cannon again. Question: How much more would 2 50's plus 250 rounds per gun weigh than the 2 7.7's of the Zero? If the 190 had 50's, it might have brought down Johnson. Obviously the 190 was out of cannon shells or her would have used them.

I think elephant hunting is a good example. If the weapon can't penetrate deep enough to destroy vital organs then why use it? Firing broadside into an Me 109 from 100 yards, will a 303 crack the engine block? I'll bet a 50 will. Will a 303 penetrate the wing spar? We've all seen gun camera footage of 50's taking a wing off of a German aircraft.

I still believe, and I may be wrong, that the British used 303's because they just happen to have a hundred million rounds in storage, and that was it.

 

[Shortround6]

You misunderstood me reguarding the Wildcat, I meant if Saburo Sakai had a pair of syncronized 50's, he could have destroyed the Wildcat without resorting to using his cannon again. Question: How much more would 2 50's plus 250 rounds per gun weigh than the 2 7.7's of the Zero? If the 190 had 50's, it might have brought down Johnson. Obviously the 190 was out of cannon shells or her would have used them.

The increase in weight would have been about 165lbs for the guns and ammo alone. Please note that the Japanese themselves did go to a 13mm version of the American Browning in the later A6M5 aircraft, but intially only one 7.7mm was replaced. Later a 13mm gun was added to each wing but even with the fuselage 7.7mm removed and a more powerful engine performance went down. It is easy to say a certain gun would have worked better if you can more than double the weight of the installed armament. The 190 might have brought down Johnson using .50 cal guns, on the other hand if it was using .50cal guns they might have run dry about the same time as the 20mm guns did meaning no attack at all after the initial damage. Maybe the .50s could have added enough to the initial damage to turn the trick?

I think elephant hunting is a good example. If the weapon can't penetrate deep enough to destroy vital organs then why use it? Firing broadside into an Me 109 from 100 yards, will a 303 crack the engine block? I'll bet a 50 will. Will a 303 penetrate the wing spar? We've all seen gun camera footage of 50's taking a wing off of a German aircraft.

Elephant hunting is still a lousy example. The natives used to use spears, no penetration to vitals. Lots of cuts and blood loss over several days lead to a dead elephant, not quite as quick as a hits to the radiator/oil cooler but same general principal.

Engines were not bullet proof. .303s, 7.62 Nato, 30-06 will all punch holes in cast iron engine blocks let alone aluminum ones. It is just that single or double hits won't twist or distort the block enough to make it stop running almost instantly. 2 or 3 finger sized holes in the cooling jacket will stop the engine just about as fast as 2 or 3 finger sized holes in the radiator however. The rifle bullets will also punch through the crankcase causing oil leaks and even the reduction gear case also causing oil leaks. Magnetos, carburetors, fuel injection pumps and other bits and pieces were also vulnerable to rifle caliber bullets. So were oil tanks and hydraulic tanks. The .50 just punched slightly larger holes in such things. Granted it could do more damage to major structural parts like spars but then if you are firing only 1/4 of the number of bullets the chances of hitting the parts of the airplane that are vulnerable to the .50 but not to the rifle calibers goes way down.

I still believe, and I may be wrong, that the British used 303's because they just happen to have a hundred million rounds in storage, and that was it.

You can believe what you want, do you have any proof for the rest of us. As has been noted already in this thread, the British did test a number of guns and types of ammo to reach their conclusion. Maybe it was a whitewash, but people using anecdotes form times well after the tests were conducted using faster firing guns and more powerful ammunition in installations that weighed much more than than the initial British 8 gun installations to "prove" the British made a mistake or were misguided in their decision sure seems like revisionist history to me.

 

[pinsog]

Yes natives used to used spears to kill elephants, and a great many of them entered the afterlife a tad ahead of schedule. Men took on tanks with sticky bombs also, but I wouldn't want to have to pay his life insurance out of my own pocket.

If a 303 will penetrate one side of the block, a 50 would go all the way out the other, or bury itself into the crank or through a piston etc. There should be no comparison in the amount of damage.

This whole thread is revisionist history. The point of doing it is, with a great deal of hindsight, to see if could we in fact have done things any better than they did.

 

[renrich]

A lot of interesting remarks in this debate. Some of the remarks I quoted earlier made by the AAF reps at the Fighter Conference probably also played a role in the RAFs decision to go with the 8-303s. Their pilots who were not expert gunners needed a lot of bullets in the vicinity of the target in order to get any hits. When talking about Japanese fighters most of us almost invariably say A6M or Zero, In reading Shores, "Bloody Shambles" I realised that a lot of Allied ACs were shot down by KI27s with two 7.7s firing through the prop and even more were shot down and this includes late in the war by KI43s with two 12.7s firing through the prop. Their victims included besides the more easily shot down Hurricanes and P40s but also Beaufighters and P47s. All our debates about the need for cannons and heavy MGs are put in a little different light by considering the effectiveness of those fighters. The P51 Bs and Cs did well with only four heavy MGs. I wonder how the six 50s in the F86s were sighted in during the Korean War? To converge or form a pattern?

 

[tyrodtom]

Did the Japanese Army aviation units have the same great loses in the war as the naval aviation units?
Being able to hold on to the more experienced pilots longer may have been a big factor in those 2 .30 cals being enough in a Ki-27 and Ki-43.

 

[Shortround6]

If a 303 will penetrate one side of the block, a 50 would go all the way out the other, or bury itself into the crank or through a piston etc. There should be no comparison in the amount of damage.

For which .50 cal?

The one in 1944 using M8 API ammo and firing at 800-850 rpm in a wing mount or the one in 1934 using M1 ball and firing at 450-500rpm through the propeller?

And I would really, really like to see a mild steel cored .50 cal bullet that smashed through part of engine block and then buried itself part way into an aircraft engine crankshaft. Got one handy?

The trouble with penetration and kinetic energy as indicators of potential damage is that conditions have to be just right to get the full effect, if you even get it then. An old book I have has got range, trajectory and penetration charts of various materials for the 30-06 M1 ball, the U.S. 30 M1906 and the early M1 .50 caliber ball round. In some mediums (sand, wood, concrete) the rifle caliber bullets, lead cores and all, will penetrate 1/2 to 2/3 the distance the .50 cal bullet will with it's steel core. Granted the .50 is making a bigger hole and doing more damage but the amount of "stuff" a military full jacket bullet will go through is rather amazing. The U.S. .30 M1906 was tested at a different time than the others but it's test results include penetrating 1/4 low grade steel plate at 400yds. Certainly not hard armor but these rifle bullets are not going to bounce off most mechanical bits and pieces in an airplane either.

The question facing the British in the late 20s, early 30s and the question we are re-hashing now is not wither the .50 caliber is more powerful than the .30/.303, it certainly was. The question was/is for a given weight of installed armament (guns, ammo, mounts, ammo boxes/chutes, gun heaters, etc) wither the .50 cal battery was more effective than than the .30/.303 battery. Effectiveness includes not only the effectiveness of single bullet hit but the probability of hitting and the ability to stay in the fight or engage multiple targets.
A F4F-3 carried four .50 cal guns that weighed 286lbs and with full ammo carried another 516lbs. Total 902lbs just for guns and ammo. A pretty effective armament in 1942.
A F4F-4 carried six .50 cal guns that weighed 433lbs and with full ammo carried another 432lbs. Total 865lbs just for guns and ammo. Also pretty effective but traded combat endurance for hitting power.
A F6F-3 carried six .50 cal guns that weighed 433lbs and with full ammo carried another 720lbs. Total 1153lbs just for guns and ammo. Pretty effective in 1944 but shows the cost of getting both hitting power and combat endurance.

A look at a few P-40s may also be helpful.

A P-40B/C with a pair of .50s in the cowl is listed at having 150lbs for the gun installation (not just guns). The four .30 cal guns in the wings are listed at 94.4lbs for the installation. Ammo weights are given as 228lbs for the .50cal ammo (380 rpg) and 127.4 for the .30 cal ammo (500rpg) for just about 600lbs total.
The P-40E with 6 guns is listed as 475lbs (army may include more bits and pieces rather than bare guns) with 432lbs for ammo for a total of 898lbs.
The P-40L "stripper" model had 4 guns for a weight of 313lbs and 282lbs of ammo for a total of 595lbs.
Both later models of P-40s are given with an average of 235 rpg. or about 18 seconds of firing time. 940 rounds total.
Please remember that these war time US planes had guns that could fire at about 800rpm rather than the 600rpm or under of the guns the British tested a number of years earlier.
An early Spitfire devoted about 685lbs to it's "military load" of guns, ammo, gunsight end even perhaps the radio. It had 2400rounds of ammo for it's .303 guns and 16 or so seconds of firing time.

 

[Ratsel]

" Engines were not bullet proof. .303s, 7.62 Nato, 30-06 will all punch holes in cast iron engine blocks let alone aluminum ones "
not so fast, may many factors to take into consideration here. the least of which is .303's punching holes in an engine block. I doubt
very much a .303 could do that. I doubt also that it could make it through the armored oilpan on a DB601/605.

 

[pinsog]

"For which .50 cal?"

"The one in 1944 using M8 API ammo and firing at 800-850 rpm in a wing mount or the one in 1934 using M1 ball and firing at 450-500rpm through the propeller? "

When I refer to the .50, I am always refering to the US Browning model. I know there were others, but for the sake of simplifying things I'll just refer to the Browning model.

I know the US improved the ammunition used in the 50 as the war progressed, but even standard ball ammo for a 50, I would think, would outperform anything they had back then coming out of a 303. Unless your loading depleted uranium bullets in a 303 and styrofoam bullets in a 50, I just dont see any comparison. Lets remember that a great portion of the ammo being spat out of the 303 was ball. I've personally fired a 3006 into an altenator from a range of about 40 feet. It did not exit. I have fired rifles ranging from 3030, 3006, 300 win mag, and even 30-378 weatherbys into trees, I fired and have seen a 50 fired into trees, I wouldn't want to have been on the other side of that forest. Whatever the standard loading of 303 rounds into the ammo belt is, I would imagine that would be the standard loading for the 50 also, so I don'tsee there being any great advantage to some sort of 303 super bullet, it all comes down to weight and velocity.

I understand that you have to hit the target, but as Thach said, "if you miss with 4, you won't hit with 8". So, I'm a newby pilot that cant shoot. So we hang 10 miniguns under the wings of my plane set to converge at 200 yards. I aim 10 feet behind my target and mash the trigger, guess what? 60,000 rounds per minute are going to go 10 feet behind the target. If I have 2 50's, 450 rounds per minute, and I'm a good shot, and I pull proper lead, then I'm going to hit the guy.

 

[Greyman]

So we hang 10 miniguns under the wings of my plane set to converge at 200 yards.

That was one of the benefits the RAF felt that was brought to the table with the new eight-gun fighter; the fact that they could create pattens with the eight different bullet groups that could decrease the chance of missing a target. The thinking being quite the opposite of your Thatch quote ... 'if you miss with four, you'll hit with eight.'

With ten miniguns you could make quite a large, dense pattern and hitting would be a lot easier.

 

[pinsog]

"That was one of the benefits the RAF felt that was brought to the table with the new eight-gun fighter; the fact that they could create pattens with the eight different bullet groups that could decrease the chance of missing a target. The thinking being quite the opposite of your Thatch quote ... 'if you miss with four, you'll hit with eight.'"

Greyman,

8 rifle caliber guns, pointed in 8 different directions was not the way to bring down any enemy aircraft. You have to put enough lead into the aircraft to actually cause damage and bring it down. When using rifle caliber machine guns, they need to be as concentrated as possible. A stray bullet or 2 is not going to bring down a DO17, He111 or JU88. Even with heavy machine guns or cannon, you need to concentrate your fire into a relatively small area so you can cause enough damage to bring an aircraft down.

 

[claidemore]

" Engines were not bullet proof. .303s, 7.62 Nato, 30-06 will all punch holes in cast iron engine blocks let alone aluminum ones "
not so fast, may many factors to take into consideration here. the least of which is .303's punching holes in an engine block. I doubt
very much a .303 could do that. I doubt also that it could make it through the armored oilpan on a DB601/605.

.303 AP ammo could very easily penetrate an engine block, as could any .30/7.62/7.92 caliber AP military round from the era.
.303 AP could penetrate up to 10mm of armor plate, not sure how thick the plate on the Daimler Benz aircraft engine oil pans was but I doubt that the Silium-Gamma alloy engine block would have much resistance to AP rounds.

Remember the guy who killed the Tsavo man eating lions? He used his .303 to punch holes through the web of railroad track (rails) to facilitate track laying. They use high grade steel for rails, this was in 1898 so thickness would have been between 3/8 and 1/2 inch(max), and he was firing round nose ammo.

The RAF was using steel cored AP rounds that were loaded to a higher velocity (around 2900 fps) than Mk VII ball .303 ammunition (2400 fps). Even the 'ball' ammo used in 1/2 of the guns in a Spit for Hurricane during BoB would have been loaded with Mk 8 ball, (the 2900 fps stuff). Mk 8 ammo was not approved for SMLE or #4 Mk1 rifles.
BTW railroad iron is what the Afghans and Pakistanis in the Khyber area use to make rifle barrels, oddly enough usually .303 rifle barrels!

 

[Shortround6]

When I refer to the .50, I am always refering to the US Browning model. I know there were others, but for the sake of simplifying things I'll just refer to the Browning model.

They are all Browning models. The point is that just like the ammo the "Browning model" evolved over time. The US military .50 cal Browning's for aircraft use fired at about 600rpm on test stands during the 1930s. In actual use the rate of fire was lower due to belt drag and other factors let alone putting a sychronizer on them. At some point in 1940 The US succeeded in raising the rate of fire to about 800-850rpm. They did not change the gun designation at this time, it stayed as the M2. Please note that the aircraft and ground guns, while both called M2's had different barrels, barrel shrouds and a few other parts that were different and different rates of fire. In 1945 they succeeded in raising the firing rate to 1150-1250 rpm but so many new parts where needed the gun was re-designated the the M3. They are all "Browning models" and all in US service but of rather different capabilities.

I know the US improved the ammunition used in the 50 as the war progressed, but even standard ball ammo for a 50, I would think, would outperform anything they had back then coming out of a 303. Unless your loading depleted uranium bullets in a 303 and styrofoam bullets in a 50, I just dont see any comparison. Lets remember that a great portion of the ammo being spat out of the 303 was ball. I've personally fired a 3006 into an altenator from a range of about 40 feet. It did not exit. I have fired rifles ranging from 3030, 3006, 300 win mag, and even 30-378 weatherbys into trees, I fired and have seen a 50 fired into trees, I wouldn't want to have been on the other side of that forest. Whatever the standard loading of 303 rounds into the ammo belt is, I would imagine that would be the standard loading for the 50 also, so I don'tsee there being any great advantage to some sort of 303 super bullet, it all comes down to weight and velocity.

This is a real side track, do you even read what is posted?

Were did I ever say that any .303 or any rifle caliber bullet was equal to the .50 cal on a one for one basis?

Were do I make any claims about a "super" bullet for the .303?

I have told you that the US changed the loading for the .50 cal at some point just before the war. The old loading was much more powerful than a .303 but it was about 14% less powerful than standard loadings used during the war. It is this less powerful ammo the British would have tested in the late 20s or early 30s.

I have given you an example of a standard 30-06 cartridge with a standard "ball" bullet. If you don'y like the penetration figures argue with the DoD or the Dept or ordnance. it is their chart I am reading, not something I made up (found on Page 104 of "Ammunition" By Melvin M. Johnson and Charles T. Haven, 1943) While the .303 isn't quite as good these bullets don't need to made of depleted uranium or any other exotic stuff to punch holes in aluminium castings.

I still haven't seen that .50 cal bullet that went partway into an aircraft crankshaft? care to share?

I understand that you have to hit the target, but as Thach said, "if you miss with 4, you won't hit with 8". ...... If I have 2 50's, 450 rounds per minute, and I'm a good shot, and I pull proper lead, then I'm going to hit the guy.

Ah, yes. the Thach quote. Nice talk from a 10-11 year veteran pilot before the war started who spent a considerable amount of time as a aerial gunner instructor. I would really like to know what was said before and after that quote to put it in context. No disrespect to Thach but not everybody had his ability.

I got a quote for you too. From a fellow my father used to shoot with when I was learning to shoot prone "Shoot for the X's, the ten's will take care of themselves." It works, it just takes some time to get to that level. But I guess that all those F4Us, F6Fs, P-40s, P-38s, P-47s and six gun P-51s were over gunned? and they had the 800-850 rpm guns.

 

[Ratsel]

I appreciate what your saying, but again, not so fast. there are various things that the .303 has to pass through just to get to the engine. not to mention the angle that it hits the engine at. realisticly, how many .303 bullets fired in combat conditions would penetrate the block? 1 in 10? 1 in 100? 1 in 1000? 1 in 10000?

 

[Shortround6]

" Engines were not bullet proof. .303s, 7.62 Nato, 30-06 will all punch holes in cast iron engine blocks let alone aluminum ones "
not so fast, may many factors to take into consideration here. the least of which is .303's punching holes in an engine block. I doubt
very much a .303 could do that. I doubt also that it could make it through the armored oilpan on a DB601/605.

This has already been answered some what but the big problem with penetrations on aircraft is that the angles could be rather extreme. Bullets that punch through 10-12 mm or armor with a 90 degree hit are deflected rather easily by much thinner armor with shallow angles of impact.
Most liquid cooled aircraft engines used cast aluminium crankcases, cylinder blocks and/or heads and cast aluminum cam/valve covers. In some cases they used cast magnesium cam/valve covers and cast magnesium crankcase covers. Radial engines used cast or forged crankcases (Wrights used forged Steel) with steel cylinder barrels with, usually, forged aluminum heads on the high powered engines. Cast aluminium or magnesium rocker box covers. If regular rifle bullets can punch though 1/4 in -3/8 in low grade rolled steel (not armor) at several hundred yds I see no reason why an aluminium casting is going to stop it given anything approaching a decent impact angle. I mean you can skip a bullet off of water but without getting ridiculous the Aluminium doesn't stand much chance.

I would also like to see that armored "Oil Pan" on a 601/605. I knew they had armored oil coolers mounted below the engine on 109s but I can't quit figure out where the oil pan is on a DB 601/605.

http://cdn.wn.com/pd/11/13/5b1af820d8521527e7fc33853c19_grande.jpg

 

[Ratsel]

haha I knew I was gonna get bitten on that when I wrote it. the lower crankcase cover is what I should have written. my appologies.

 

[Shortround6]

I appreciate what your saying, but again, not so fast. there are various things that the .303 has to pass through just to get to the engine. not to mention the angle that it hits the engine at. realisticly, how many .303 bullets fired in combat conditions would penetrate the block? 1 in 10? 1 in 100? 1 in 1000? 1 in 10000?

penetrate the block to do what?

Seize the engine up instantly?

or just poke holes in it so the coolant, oil leak out and the engine seizes up in a few minutes?

And it rather depends on the angle of fire how much stuff the bullets have to pass through to hit the engine. From the rear they might have to pass through quite a bit, from the front not so much and from top or sides maybe and engine mount (that should stop them) or maybe just some sheet metal cowling. It the Bullets are coming from the rear there may be a whole lot of stuff they could hit to screw the plane up without making it to the engine proper.

Everybody makes so much about the liquid cooled radiators being so vulnerable to single bullets but you have an engine that is 5-6 feet with a number of cast cooling passages exposed to being punctured by gun fire and everybody acts like they are bullet proof.

 

[pinsog]

QUOTE=Shortround6;807326]They are all Browning models. The point is that just like the ammo the "Browning model" evolved over time. The US military .50 cal Browning's for aircraft use fired at about 600rpm on test stands during the 1930s. In actual use the rate of fire was lower due to belt drag and other factors let alone putting a sychronizer on them. At some point in 1940 The US succeeded in raising the rate of fire to about 800-850rpm. They did not change the gun designation at this time, it stayed as the M2. Please note that the aircraft and ground guns, while both called M2's had different barrels, barrel shrouds and a few other parts that were different and different rates of fire. In 1945 they succeeded in raising the firing rate to 1150-1250 rpm but so many new parts where needed the gun was re-designated the the M3. They are all "Browning models" and all in US service but of rather different capabilities.
I knew the late war 50's had a REALLY high rate of fire. I was unaware that the rate of fire ever dropped below 550 or 600 rpm, but the US only had what 2 or 3 fighters with sycronized guns didn't we? P39, P40, Early Allison powered Mustang,

This is a real side track, do you even read what is posted?

Were did I ever say that any .303 or any rifle caliber bullet was equal to the .50 cal on a one for one basis?

Were do I make any claims about a "super" bullet for the .303?


I have told you that the US changed the loading for the .50 cal at some point just before the war. The old loading was much more powerful than a .303 but it was about 14% less powerful than standard loadings used during the war. It is this less powerful ammo the British would have tested in the late 20s or early 30s.
I was aware of this, it agrees with everything I have read.

I have given you an example of a standard 30-06 cartridge with a standard "ball" bullet. If you don'y like the penetration figures argue with the DoD or the Dept or ordnance. it is their chart I am reading, not something I made up (found on Page 104 of "Ammunition" By Melvin M. Johnson and Charles T. Haven, 1943) While the .303 isn't quite as good these bullets don't need to made of depleted uranium or any other exotic stuff to punch holes in aluminium castings.
I don't doubt your information at all. It sounds correct to me.

I still haven't seen that .50 cal bullet that went partway into an aircraft crankshaft? care to share?
I think I should slightly rephrase that into "punching through the block and mushrooming up against the crankshaft".

Ah, yes. the Thach quote. Nice talk from a 10-11 year veteran pilot before the war started who spent a considerable amount of time as a aerial gunner instructor. I would really like to know what was said before and after that quote to put it in context. No disrespect to Thach but not everybody had his ability.
If I recall correctly, he was concerned about the increase in weight of the F4F4 with no change in hp, and subsequent reduction in performance compared to the F4F3. He told the US Navy that it did no good to put 6 guns on a fighter if you cant bring them to bear, your better off with 4, if you cant hit with 4 then you will miss with 8.

I got a quote for you too. From a fellow my father used to shoot with when I was learning to shoot prone "Shoot for the X's, the ten's will take care of themselves." It works, it just takes some time to get to that level. But I guess that all those F4Us, F6Fs, P-40s, P-38s, P-47s and six gun P-51s were over gunned? and they had the 800-850 rpm guns.[/QUOTE]

I agree with that last quote 100%

I think the fighters listed had the perfect weapons setup to battle other FIGHTERS. When you move into heavy bombers, of course, cannon was the only good solution.

 

[claidemore]

I appreciate what your saying, but again, not so fast. there are various things that the .303 has to pass through just to get to the engine. not to mention the angle that it hits the engine at. realisticly, how many .303 bullets fired in combat conditions would penetrate the block? 1 in 10? 1 in 100? 1 in 1000? 1 in 10000?

Well, 1 in 1000 would be enough... 2400 rds in a Spitfire Mk 1. Of course some of the other 999 rounds might hit something else, like an oil or coolant line, which even a .22 LR could break.

I spent a few fun filled afternoons in a farmers field shooting derelict cars and trucks from the 40's and 50's with .22 LR, 357 Mag (handgun), .303 , .270 Win and 12 gauge shotgun slugs. Engine blocks easily penetrated by the rifle rounds. Not neat little round holes though, these were cast iron blocks and the hunting ammo we were using blew big jagged holes. Never took one apart to see how deep the bullets penetrate, probably not that far, but there were oil and coolant leaks all over the field. I do recall shooting through the rad and fan of one car and got no penetration on the engine,I don't remember if that was with a rifle or the pistol.
Wouldn't dream of doing the same thing today, pretty damaging to the environment, but back then we didn't think about that.

 

[Ratsel]

did somebody pee in your cornflakes this morning ( j/k ). not saying that the engines were not vunerable, the Allison V-1710 was a prime example. just saying that its more probably that the engine electrical/coolant ~ oil lines/ fuel system, etc would be hit first and bring the plane down.

I'm sure a guy with a model 1911 colt w/ a .45apc round firing from the ground could bring a plane down with a very lucky shot.

claidemore,

I never punched a hole in a engine with a .303, but I have with a shotgun w/ slug.