.50 Cal vs 20 mm Hispano - Ground Attack

[Venturi]

13 hours ago, JtD said:

I'm starting to wonder why the IL-2 didn't come with a battery of 12.7mm UB guns, given that they were considerably better than the M2 and the M2 appears to have been the be all end all weapon. In a wing that large, they could have easily fitted a dozen UB's giving it 100% more firepower for the same weight as the eight M2's on the P-47. Which apparently is already better than 4x20, which for the same reasons must surely be better than 2x23.

 

My guess is the Soviets weren't stupid and used cannons because they were both, more effective and more efficient. Just like every nation that had a working 20mm cannon (or larger) made use of it in their aircraft - be it fighter or ground attack or anything else with front firing guns. Really, it's hard to find front line aircraft outside of the US that didn't feature 20mm+ cannons. And imho that's not because everyone outside the US was stupid, imho it is because the US failed at mass producing a reliable 20mm cannon.

 

No the Soviet’s weren’t stupid. But, they placed a premium on aircraft maneuverability and besides which, they didn’t have a lot of spare weapons to go around. 

 

Anyways, the IL-2 was a ground attacker. And like I said before, if you're not shooting at high deflection, fast moving targets, then area saturation isn’t as important as the effect on target - and the Hispano and other HIGH velocity cannons were better than the 50BMG at effect on target per round, IE, hitting ground targets - which could be and usually were targets that needed more pounding than aluminum-skinned aircraft.

 

It’s not about the US not developing a 20mm cannon. It’s because the right weapon for the job was the 50BMG. The other nations were more concerned about intercepting BOMBERS and that is why they went with a MG/cannon setup. The MGs originally being for the fighters (fast moving targets with snap deflection shots) and the cannon being for tougher targets. This is why the Brit’s went away from 303s to a mix of cannon and MG.

 

By the way, the mix of MG and cannon was a European philosophy - not better or worse, just different trade offs. In the interwar years, the US experimented with such a mixture of armament, with the 50BMG filling the role of the cannon in the Euro planes (a good example is the original Brewster Buffalo, with armament of 1x50BMG, 3x30BMG). This when the contemporary Euro planes had only rifle caliber MGs, no heavy MGs or cannon. It just turned out that it was simpler and more efficient while being just as effective to replace rifle caliber MGs throughout all mounting points with heavy caliber MGs on most fighters. And, the 50BMG damn sure was effective.

 

Is 8x50BMG better than 8xHispano 20mm? Probably not. But that’s not the comparison. The comparison is 8x50BMG vs 4xHispano 20mm, or more likely to be found in the anti-fighter role, 2xHispano and 4x303. The 8x50BMG wins over the 4x cannon in the anti-fighter role due to simply the greater number of projectiles in the air - all of which may be lethal, individually - while losing in the anti-ground role. 8x50BMG is even more markedly superior to the 2x cannon setup in the anti-fighter role. Keep in mind that all these were very effective set ups, though - as proven historically. It’s just that a large amount of lead is needed to saturate a given area, at one point in time, for maximally effective slashing attacks. And high altitude attacks were generally slashing type gunnery solutions with much higher closing speeds and with far less aircraft maneuverability than at low altitudes. 

 

I will say that the 4xHispano is no slouch in the air (although inferior to the 8xBMG setup), and better then the Jug’s 8x 50s in the ground attack role (and better for bomber intercept, for similar reasons - although this point is moot given the historical situation). Even so, I invite you all to examine some photos or videos (or even better get up and go to a museum and  see for yourself) of the numerous venting areas on the top decks of many tanks, and actually the vast majority of non-tank AFVs, of the WW2 period (which after all was a large portion of the panzerkorps/red army tank division). Look for areas that might be cripple-able by a hundred or so rounds of heavy caliber MG using AP. I think you would find there are areas on that engine deck that are conceivably vulnerable even to supposedly lowly 50BMG.

Additionally I would challenge the idea of the calculations in that ”weapon effectiveness” webpage which seems to be taken as gospel here on these forums. Actually, it is far more complex. 

 

The major reason that page is wrong, although it is interesting, is that the author of it is simply using “energy” as a metric for effectiveness on target. But as any student of physics will tell you, energy can be converted into different forms, but not all forms are the same in their ability to do work.

 

For instance, the KE of the cannon shell explosive blast is reduced by the inverse square law, and much is spent on empty air - and a large portion of that energy is lost. Similar to fragments - they will not all hit the plane when the shell bursts. In fact, a majority may not hit. Whereas the KE of the projectile is always, if it hits the plane at all, used to bore a hole through whatever is in its way (engine block, radiator, pilot, control cable).

 

Edited September 22, 2019 by Venturi

[JtD]

Report of the Joint fighter conference:

 

Commander R.E.Harmer, USN, speaking about night fighter guns: "They should be cannon. I am not satisfied with the 0.50 cailbre guns"

 

Commander J.P.Monroe, USN, Armament Branch, Bureau of Aeronautics: "To give you some idea of the 50 versus the 20 and dispel a lot of ideas that have bothered us, I would like to give you a comparison. When somebody goes from four 50's to two 20's, to the layman that means a decrease in fire power. Actually, quite the reverse is true. In the horsepower of the gun, one 20 is euqal to three .50-calibers. In the actual rate of fire delivered at the target, one 20 equals three 50's; in kinetic energy at 500 yards, one 20 equals two and one-half 50's.

That addes up to four 20's equaling twelve 50 calibers, judged by those standards. Of course, you have other advantages with the 20. You have much greater penetration of armor. The 20 will go through 3/4 inch of armor at 500 yards, while the .50 cal will go through only .43. In addition to that you have one more great advantage - that is, you can have longer and ore frequent bursts without damage to the gun with the 20 than you can have from the .50 cal. That is important for the strafing airplane, because they are burning up their barrels and ruining their guns on one flight. [...]Of course, you have disadvantages. You have a heavier installation, one-half as much ammunition for the same weight. Our standard ammunition in the Navy is 400 rounds in one gun. The Fleet has set up 30 seconds of ffire as a minimum requirement for the .50 cal. gun. We can't do that with the 20, so we give them 200 rounds. The 20 is lethal enough to get far more results out of that 200 rounds than the .50 ever will get out of the 400 rounds. [...]

 Another disadvantage of the 20 is the time of flight. Out to 500 yards you've got three-quarters of a second as against a .62 for the 50. These airplanes go 450 to 500 feet per second, and in one-tenth of a second 35 to 40 feet."

 

Colonel L.B.Coats, USAAF: "I believe the feeling in the Army generally is that we would like to have a lethal density pattern. The most bullets going across one place at a given instance. We would like to have the smallest caliber gun that can do the job."

 

Group Captain H.W.Dean, RAF: "In the first place, our policy on caliber is pretty well in line with the Navy. [...] right now, and since the beginning of the war, we have had the 20 and we like it."

[LColony_Kong]

8 hours ago, Bremspropeller said:

 

A large share of devaststion was done by bombs and rockets. While a strafed column of trucks might look impressive, it's after all just a collection of holes.

The same is true for the 20mm - the holes are bigger and a good deal more jagged, though.

 

The whole point of this thread seems to be showing how devastating 8 cal 50s are.

Well, 4 20mm guns are just about as devastating in kinetic performance, plus they have additional HE capability.

 

20mm >>> cal 50.

 

Theory is hard physics.

No amount of "actual results" or some clouded memories of allegedly turning over battlehips and sinking Tiger tanks will change that.

You guys add up destructive power without any consideration whatsoever to what is actually being hit.

 

Virtually ANY ground target that a 20mm or 50 cal could kill on the ground would be equally dead if hit by either. It is utterly ridiculous to make anything out of the fact that the hole in a truck from a 20mm is bigger, which the 50 cal would already have been overkill. Or are we going to seriously have to argue about whether killing a truck is significantly easier with  20mm?

 

Contrary to myth, aircraft cannons were not very effective against tanks. And almost any conceivable ground target that was not a tank in ww2 was soft enough that have a 20mm vs a 50 would be meaningless.

 

If the guns are both more or less overkill for soft targets, Ill take my extra ammo and saturation ability (that comes with 50s)

[unreasonable]

18 minutes ago, Lord_Flashheart said:

You guys add up destructive power without any consideration whatsoever to what is actually being hit.

 

Virtually ANY ground target that a 20mm or 50 cal could kill on the ground would be equally dead if hit by either. It is utterly ridiculous to make anything out of the fact that the hole in a truck from a 20mm is bigger, which the 50 cal would already have been overkill. Or are we going to seriously have to argue about whether killing a truck is significantly easier with  20mm?

 

 

Absolute rubbish. A 50 cal round hitting a truck full of infantry will go straight though it, and the people in it, perhaps disabling 2-3 men, and maybe - but probably not - disable the vehicle.  A 20mm AP shell would do much the same thing: but a 20mm HE shell would likely disable every infantryman in the truck.   You clearly have no idea what you are talking about. 

[JtD]

30 minutes ago, Lord_Flashheart said:

Virtually ANY ground target that a 20mm or 50 cal could kill on the ground would be equally dead if hit by either. It is utterly ridiculous to make anything out of the fact that the hole in a truck from a 20mm is bigger, which the 50 cal would already have been overkill. Or are we going to seriously have to argue about whether killing a truck is significantly easier with  20mm?

 

A 20mm round exploding inside of a truck does a lot more damage than a 12.7mm/20mm round going through. There are a very few spots you need to hit if you want to disable a truck with AP rounds - though the chances are pretty good if you hit it a hundred times. Chances to disable the same truck are much better with explosive rounds. Starts already in the drivers cabin, an AP round goes in and out, and unless the driver in in the path, nothing but two holes happened. A HE round goes in, explodes, leaves a bloody mess in the cabin and two dozen holes on its way out. Same is truck for a lot of other spots.

 

Then all armies featured lightly armoured vehicles, be it APC's or some artillery behind shielding or scout cars or whatever. As mentioned above, the AP capabilities of the 20mm are significantly better than of the .50, even with standard AP rounds. And if there's half an inch of armour, the chances are the .50 bounces of, while the 20mm creates havoc.

 

With Hispano APIII kind of ammunition, the difference is extreme - APIII being capable of penetrating two inches of armour at 400 yards. And that's indeed sufficient to successfully attack the 30mm armour of Pz IV's. Wasn't used on a general basis, though, because German tanks weren't that common and the RAF went with the SAP&HEI round.

[Gambit21]

“A” 50 cal round?

How about hundreds?

 

Again dead trucks vs deader trucks - stupid debate at this point.

[LColony_Kong]

3 minutes ago, unreasonable said:

 

Absolute rubbish. A 50 cal round hitting a truck full of infantry will go straight though it, and the people in it, perhaps disabling 2-3 men, and maybe - but probably not - disable the vehicle.  A 20mm AP shell would do much the same thing: but a 20mm HE shell would likely disable every infantryman in the truck.   You clearly have no idea what you are talking about. 

Yes, because only 1 solitary 50 cal round will hit the truck.

 

Yes, because 20mm HE filler of 6-11 grams is apparently a nuclear bomb in your eyes.

 

The fact that you are even questioning the lethality of 50cals on soft targets being more than sufficient is completely nuts. A truck that gets strafed by 50 BMG or 20mm hispano is DEAD.

[ZachariasX]

20 minutes ago, Lord_Flashheart said:

Or are we going to seriously have to argue about whether killing a truck is significantly easier with  20mm?

No. It‘s just that the 8x .50 weights more than other solutions and you have to be fine with having the weight (and space) penalty on your aircraft design. That is the true downside besides giving you considerably less options than a cannon on how to deal with a target. And it turns out, designers are generally not ok with that. For the Jug it was ok (and the BMG was the only  gun at hand at the time besides peashooters) being so much more powerful high up and as when they had to plow mud, the Luftwaffe was largely extinct. It is a very special case. No single engine fighter before and after ever used this weapon arrangement again. For good reason. And the reason was not that you couldn‘t be mean to people on the ground.

[JtD]

Certainly, the requirement of hitting the same target much more often is not beneficial. And while dead is dead, the guy with 4x20 gets to go in quicker, fly away sooner without having spend half as much ammo - for the same result, with a lighter armament.

 

And for what it's worth, it's not the 6grams of explosives that kill, it's the 120 grams of razorsharp splinters.

[LColony_Kong]

2 minutes ago, JtD said:

 

A 20mm round exploding inside of a truck does a lot more damage than a 12.7mm/20mm round going through. There are a very few spots you need to hit if you want to disable a truck with AP rounds - though the chances are pretty good if you hit it a hundred times. Chances to disable the same truck are much better with explosive rounds. Starts already in the drivers cabin, an AP round goes in and out, and unless the driver in in the path, nothing but two holes happened. A HE round goes in, explodes, leaves a bloody mess in the cabin and two dozen holes on its way out. Same is truck for a lot of other spots.

 

Then all armies featured lightly armoured vehicles, be it APC's or some artillery behind shielding or scout cars or whatever. As mentioned above, the AP capabilities of the 20mm are significantly better than of the .50, even with standard AP rounds. And if there's half an inch of armour, the chances are the .50 bounces of, while the 20mm creates havoc.

 

With Hispano APIII kind of ammunition, the difference is extreme - APIII being capable of penetrating two inches of armour at 400 yards. And that's indeed sufficient to successfully attack the 30mm armour of Pz IV's. Wasn't used on a general basis, though, because German tanks weren't that common and the RAF went with the SAP&HEI round.

-No it doesn't in the sense that both rounds will completely obliterate the target. Apparently you didnt read what I said. 1 50 call or 1 20mm are BOTH very unlikely to stop a truck cold unless the placement is extremely good. Hundreds of rounds from both make a dead truck.

 

-50cals have sufficient armor penetration to destroy ANY light armored ww2 vehicle. Armored cars, half tracks etc. Some of those vehicles are vulnerable to 7.62.

 

-30mm of armor on a Panzer 4 is not likely to be penetrated by 20mm AP at any realistic angle of impact from an aircraft, at realistic ranges. 20mm under matches 30mm of armor, and at a 45degree dive angle the slope multiplier would make the armor nearly 60mm thick effectively. And that assumes no compound angles. Both 50 cal and 20mm could mess up engine decks, gun barrels, etc.

 

3 minutes ago, ZachariasX said:

No. It‘s just that the 8x .50 weights more than other solutions and you have to be fine with having the weight (and space) penalty on your aircraft design. That is the true downside besides giving you considerably less options than a cannon on how to deal with a target. And it turns out, designers are generally not ok with that. For the Jug it was ok (and the BMG was the only  gun at hand at the time besides peashooters) being so much more powerful high up and as when they had to plow mud, the Luftwaffe was largely extinct. It is a very special case. No single engine fighter before and after ever used this weapon arrangement again. For good reason. And the reason was not that you couldn‘t be mean to people on the ground.

A Jug or P-38 can carry more ordnance (significantly more) than any of the dedicated 20mm armed attack planes like the il2. The tempest is another matter obviously. But it is clearly not the case that said weight = worse platform. Even a P-51 can outmatch dedicated strike aircraft during ww2 for ordnance and still have better performance.

 

I dont deny there are disadvantages to the 50 cal setup, but pointing them out does not make them the overall worse solution. And neither does pointing out that it was never done again. Alot of stuff changed very fast during this period. Dont forget that we went from 450mph fighters in 1945 to Mach 2 fighters shooting missiles just 15 years later. The decades after ww2 were a massive period of flux.

[ZachariasX]

16 minutes ago, Gambit21 said:

How about hundreds?

What weapon would you prefer, one that requires you to hit two, three times or one that requires you to hit „hundred“ times?

[unreasonable]

5 minutes ago, Lord_Flashheart said:

Yes, because only 1 solitary 50 cal round will hit the truck.

 

Yes, because 20mm HE filler of 6-11 grams is apparently a nuclear bomb in your eyes.

 

The fact that you are even questioning the lethality of 50cals on soft targets being more than sufficient is completely nuts. A truck that gets strafed by 50 BMG or 20mm hispano is DEAD.

 

More rubbish.  Do you remember saying "Virtually ANY ground target that a 20mm or 50 cal could kill on the ground would be equally dead if hit by either."?

 

This is simply not true, as anyone with even rudimentary military knowledge would know. You clearly have none. 

 

No-one is saying that the 50 cal solution was not adequate, simply that 20mm cannons were better: as every air force eventually agreed, once they had worked out how to make a functioning 20mm cannon (something the US struggled with, for reasons that are not entirely clear).  But we have people here blindly insisting that the 50 cals were as good or even better: as clear a case of blindness to empirical evidence, nationalistic bias and NIH as I have ever seen on this forum, even from people with squad names like =SS-JG/666=   Crump would be proud of you guys.

 

 

 

 

 

[ZachariasX]

7 minutes ago, Lord_Flashheart said:

But it is clearly not the case that said weight = worse platform.

The same aircraft is a better aircraft without unnecessary weight. Always.

[LColony_Kong]

8 minutes ago, JtD said:

Certainly, the requirement of hitting the same target much more often is not beneficial. And while dead is dead, the guy with 4x20 gets to go in quicker, fly away sooner without having spend half as much ammo - for the same result, with a lighter armament.

 

And for what it's worth, it's not the 6grams of explosives that kill, it's the 120 grams of razorsharp splinters.

Yes of course the damage is done with the shrapnel.

 

-In no case are we hitting the truck with 1 round. In either case you are saturating the truck with fire. Those extra 50 cal rounds ARE shrapnel.

4 minutes ago, unreasonable said:

 

This is simply not true, as anyone with even rudimentary military knowledge would know. You clearly have none. 

 

 

 

 

 

 

No, I just have ten years of military service with experience on one of the weapons we are discussing, and ive seen both THIRTY MM and 50 cal hit real people.

[unreasonable]

1 minute ago, Lord_Flashheart said:

Yes of course the damage is done with the shrapnel.

 

-In no case are we hitting the truck with 1 round. In either case you are saturating the truck with fire. Those extra 50 cal rounds ARE shrapnel.

 

No, you really cannot have it both ways: one moment the argument is that 50 cals are superior because they have a greater dispersion, but now they are effective because they are saturating a truck with rounds.  You cannot do both.  The only possible argument for more but lighter weapons in ground attack is a larger beaten zone.  But that comes at the expense of effectiveness per hit.   

[LColony_Kong]

1 minute ago, unreasonable said:

 

No, you really cannot have it both ways: one moment the argument is that 50 cals are superior because they have a greater dispersion, but now they are effective because they are saturating a truck with rounds.  You cannot do both.  The only possible argument for more but lighter weapons in ground attack is a larger beaten zone.  But that comes at the expense of effectiveness per hit.   

Lol what? How do you think they saturate the truck? through dispersion. six fifties firing at 800 rounds per minute with a harmonization pattern is going to SHRED a truck, or people, or ammo dumps, etc. And so will 20mm.

[JtD]

9 minutes ago, Lord_Flashheart said:

-No it doesn't in the sense that both rounds will completely obliterate the target. Apparently you didnt read what I said. 1 50 call or 1 20mm are BOTH very unlikely to stop a truck cold unless the placement is extremely good. Hundreds of rounds from both make a dead truck.

 

Well, that's what I said. In the part that you quoted, as a matter of fact.

 

11 minutes ago, Lord_Flashheart said:

-50cals have sufficient armor penetration to destroy ANY light armored ww2 vehicle. Armored cars, half tracks etc. Some of those vehicles are vulnerable to 7.62.

 

Only if your definition is that anything that withstands a .50 is not lightly armoured anymore. But, as it were, several vehicles I refer to as lightly armoured featured amour between 10 and 20mm, which are hard to crack with a .50 from the air. Easily with a 20mm, though.

 

17 minutes ago, Lord_Flashheart said:

-30mm of armor on a Panzer 4 is not likely to be penetrated by 20mm AP at any realistic angle of impact from an aircraft, at realistic ranges. 20mm under matches 30mm of armor, and at a 45degree dive angle the slope multiplier would make the armor nearly 60mm thick effectively. And that assumes no compound angles. Both 50 cal and 20mm could mess up engine decks, gun barrels, etc.

 

First, no sane pilots in real life attacks a tank at a 45° dive angle. That's stupid and insane and can only be found in computer games where you can hit refly after you crashed into the gound. And the APIII can defeat 30mm of armour under normal combat conditions, because it was designed for that. It works the same way a 30mm GAU-10 works, just on a smaller scale. It's a tungesten carbide round and can defeat 30mm at 600 yards at a 30° impact angle.

 

12 minutes ago, Lord_Flashheart said:

In no case are we hitting the truck with 1 round. In either case you are saturating the truck with fire. Those extra 50 cal rounds ARE shrapnel.

 

So two shrapnel vs. twenty. I'd still go with twenty.

 

4 minutes ago, Lord_Flashheart said:

six fifties firing at 800 rounds per minute with a harmonization pattern is going to SHRED a truck, or people, or ammo dumps, etc. And so will 20mm.

 

Yes, and the 20mm will do it quicker with less effort. That's why they are better for ground attack.

[LColony_Kong]

1 minute ago, JtD said:

 

 

So two shrapnel vs. twenty. I'd still go with twenty.

 

 

Yes, and the 20mm will do it quicker with less effort. That's why they are better for ground attack.

Except no, because in both cases you are hitting the target with a burst. There is no two vs twenty. There is no "quicker," You are hitting the target with a hail of 20mm and 50 cal, in both cases the target is obliterated.

[unreasonable]

11 minutes ago, Lord_Flashheart said:

Lol what? How do you think they saturate the truck? through dispersion. six fifties firing at 800 rounds per minute with a harmonization pattern is going to SHRED a truck, or people, or ammo dumps, etc. And so will 20mm.

 

P-47s would do well to hit a truck with a single round. Look at the gun cams of strafing - they are rarely flying straight at a target: usually they are walking the shots through the target area, starting at ranges well beyond the harmonization point for air-air combat. A single truck is a very difficult target for a fast fighter, which is why they would rather attack down the length of a road packed with a convoy rather than across.  

 

The P-38s have a tighter pattern while strafing, with their nose mounted battery, but P-47s strafing are all over the place.

 

 

Edited September 22, 2019 by unreasonable

[LColony_Kong]

1 minute ago, unreasonable said:

 

Look at the gun cams of strafing - they are rarely flying straight at a target: usually they are walking the shots through the target area, starting at ranges well beyond the harmonization point for air-air combat. A single truck is a very difficult target for a fast fighter, which is why they would rather attack down the length of a road packed with a convoy rather than across.  

 

The P-38s have a tighter pattern while strafing, with their nose mounted battery, but P-47s strafing are all over the place.

 

 

Not even sure what your point here is. Also you know that the guns are still effective and providing a decent beaten zone outsize the middle of the harmonization pattern right?

[JtD]

11 minutes ago, Lord_Flashheart said:

Except no, because in both cases you are hitting the target with a burst. There is no two vs twenty. There is no "quicker," You are hitting the target with a hail of 20mm and 50 cal, in both cases the target is obliterated.

 

And the burst for the 4x20mm doesn't need to be even half as long as that for the 6x50. That's why they are better for ground attack.

[LColony_Kong]

6 minutes ago, JtD said:

 

And the burst for the 4x20mm doesn't need to be even half as long as that for the 6x50. That's why they are better for ground attack.

Lol. At any burst length likely to actually hit the target, the difference would be meaningless. Again, this is like shooting a man with a .308 or a 50bmg and pointing out that one is "more dead"

 

Also why always the 4 20mm as the comparison? Most cannon armed fighters in ww2 carried two or 1 cannons, not 4. The Tempest is really is not the ordinary.

Edited September 22, 2019 by Lord_Flashheart

[Bremspropeller]

3 hours ago, Ehret said:

I assumed US troops with combat vehicles and trucks. Not fuel starved and horse drawn Heer.

 

Mobilzed Heer would have sich fine toys as a multi-barrel 20mm Flak gun they'd use for ground-air and gound-gound.

Heer would also not have to carry around a useless BMG.

 

Heck, the Wehrmacht even thought the FG42 (7.92X57) was too powerful for full auto. Had they thought otherwise (and had they not been butthurt about it being a Luftwaffe gun), there had been lots of more serious toys on the battlefield - instead of just those pesky K98K.

 

3 hours ago, Ehret said:

First, the US gained not just air superiority but air supremacy at the end. The outproducing wasn't factor at the beginning and yet P-47s done well. The other type of western fighter which did extremely well was the F6F Hellcat and even the F4Fs managed to hold their own. Both Japanese and LW's fighter carried varied armament including rifle caliber machine guns in noses for relatively long time. The US fighters with 6-8x 0.50" weren't generally out-gunned especially considering difference in fighters size and robustness.

 

But not becuse of the allmighty cal 50, but because the other side ran out of gas and pilots.

The Fw 190 is about half the volume and half the max TOW of the late P-47, yet it has a superior firepower.

 

3 hours ago, Ehret said:

The P-47D has about 2.6x of raw destructive power of 1x 20mm; I basically said it myself. However, there are twice the projectiles in flight and guns have enough ammo to shot for twice as long. It changes how you can engage; you can take low probability shots more readily. Do you deny that?

You can afford to do posture shots to make the enemy break; something you need to do as quickly as possible if your wing-man got a six.

You can "walk" bullet stream to the target - something which happens often in historic gun camera films.

 

If there's flak around, you'll refrain from doing all those things that look cool on the range.

There it'll be "one put, haul butt". The 20mm wins there hands down.

 

To remind you people of the initial point of the thread:

The 20mm is superior because it can do the same or more damage with less rounds (and less guns), requiring less installed weight, making room for other installations, such as gas.

 

Writing that 8x50 cal is devastating is funny, because you need precisely that - eight - to make a comparable impact at the target as less than half the number of 20mm guns would do.

 

 

[sevenless]

It reminds me of the debate the germans had prior to introducing the MK 108 as an effective anti-bomber weapon. Of course you can shoot down a bomber with 20mm but you more effectively can do that with 30mm. The important point is to make shooting down targets more efficient for the young and inexperienced pilots and exactly here wins the higher caliber weapon, because you only need to score 1-3 hits instead of 20-25 hits to get the job done. Yes 0,50 cal can do the job but 20mm can do it more efficiently.

 

Edited September 22, 2019 by sevenless

[unreasonable]

46 minutes ago, Lord_Flashheart said:

Not even sure what your point here is. Also you know that the guns are still effective and providing a decent beaten zone outsize the middle of the harmonization pattern right?

 

Your point is that a truck will be shredded whether hit by 50 cal or 20mm - because there will be multiple 50 cal hits.  My point is that the gun cams - or even the dispersion pattern on a fighter approaching a ground target at 400mph - demonstrate that this is very unlikely in reality.  Much more likely is a single hit. Hence the importance of the effectiveness of the hit.

 

 

[JtD]

11 minutes ago, Lord_Flashheart said:

Lol.

Thank you for the polite tone you keep using. It makes your points much more valid.

 

11 minutes ago, Lord_Flashheart said:

At any burst length likely to actually hit the target, the difference would be meaningless. Again, this is like shooting a man with a .308 or a 50bmg and pointing out that one is "more dead"

You need some time on target, as not every round you fire is a hit. In particular when firing at a moving target with possible partical cover from several hundred meters out. It is a fact, that not everytime someone fired .50's from aircraft at a vehicle they scored dozens of hits. Not every vehicle got destroyed when it was strafed, in particular when it was defended and when there were several of them. Many of them were just damaged, starting with two simple holes in the canvas. I don't know where you take the certainty from claiming otherwise.

 

18 minutes ago, Lord_Flashheart said:

Also why always the 4 20mm as the comparison? Most cannon armed fighters in ww2 carried two or 1 cannons, not 4. The Tempest is really is not the ordinary.

Because that the question in the opening post - 4x20 or 6/8 .50ies or a mix. Plus, in a weight equivalent installation, it's 4 20mm vs. 6 0.50.

 

If you want to compare 1 20mm vs. 8 .50 then the question really is "is more more effective". And yes, it is. A totally pointless comparison.

 

FWIW, 4 20mm cannons armed planes that I can think of immediately: P-51, P-61, F4U, Beaufighter, Mosquito, Hurricane, Typhoon, Tempest, Spitfire, Firefly, Fw190, Ki-84 & N1K.

[unreasonable]

18 minutes ago, JtD said:

Thank you for the polite tone you keep using. It makes your points much more valid.

 

Well I am probably guilty of overstepping the bounds of good manners as well.   Sorry about that Mr_Flashheart.  It is just frustration at what looks like an empirical argument - which then proceeds to ignore all the actual empirical evidence.  A bit like trying to argue with your significant other about the necessity of her clothing and cosmetics expenditure. 

 

At some point you just have to let them get on with it. Time to watch some rugby. 

[ZachariasX]

1 hour ago, sevenless said:

It reminds me of the debate the germans had prior to introducing the MK 108 as an effective anti-bomber weapon.

Indeed. Or like going from 7.6 to 5.5 mm for infantry cartridges.

 

In essence, whatever you are facing, you have with ANY gun always the same problem, to solve.

 

1) Can you hit the target?

2) How long do you have the possibility to hit a target?

3) How many times do you have to hit it for the target being neutralized?

4) How many shots can you bring and in process how many targets can you neutralize before you have to go home?

 

1) It's quiet obvious that this is conditio sine qua non. It also shows how convenient a fast bullet is, if you have something that's difficult to aim at. A single moving soldier, a fast fighter, or maybe a rather immobile, large bomber? For the first you want a very, very fast bullet to make your life easy. For the second one, a fast bullet will do, even though the very fast will be more efficient. For the third one, you get away with a slower bullet.

This alone shows that small, fast cartridges are more suitable for the infantery, while the larger your target gets, this becomes less of an issue. The important thing is, you still have to be able to neutralize your target with the first shot/burst.

 

2) This one make it clear that elusive targets require the highest fire rate possible to deliver force on the target.

 

3) Short firing solutions as you have in air combat make this most inportant, as it is most often not possible to eliminate your mark with one hit.

 

4) This is especially important for infantry that can carry hardly anything as well as light, maneuverable aircraft. The more weight constrained you are, the more important the lightest combination of factors become, that results from completing 1)-3).

 

For the soldier, it is clear that the 5.5 mm is the better choice, as he can neutralize more soldiers than with 7.6 mm. Why? The faster bullet makes him hit more frequently and on top of that he can bring more ammo due to lighter rounds AND a lighter gun. he is more powerful due to two factirs. *)
 

For the aircraft, it's different. We see that 1) and 2) are similar enough between the Hispano V and the .50 BMG. But regarding 3), it is evident that I have to hit many more times. This is bad. So far, clear win for the Hispano. Now, 4). Some say, uh, ok, I'll fire three times longer (don't we love spaying?). The problem there is, it is not the shooter who decides how long your firing solution will last. So this is clearly no argument. This is why we just put in more guns. Here, twice as many guns. It helps for 3) (it halves that problem), but it works against 4) as instead of another barrel, you could have brought more bullets for future business. Thus, going down that road starts really working against you, no matter how cool so many barrels must look like on an aircraft.

 

Both the P-47 and the Lightning could only be armed to the gills because there were no defending fighters to speak of to counter them. Imagine Imagine a fully loaded flight of 8 P-47 alone 500 km inside German territory. The Germans had radar, they had ground control. Loaded like that, the P-47 would be nothing but dead. The Tempest? Did that job.

 

Spray is just wasting ammo that should have been on the target. It is stupid to bring 8 guns when only 2 at the time can hit something. You much rather just bring two, but learn to hit. The idea that you have time for spraying around on ground targets with all this ammo is simply preposterus. However if you really can do that, you better bring some canisters of napalm, then overflying the helpless shmocks, gear down, flaps down, you drop it on them. Would be more effective, as it brings hurt inside the trenches. But this is not the environment you design an aircraft for.

 

 

 

*) I remember, when the Swiss Army introduced the smaller caliber SIG550, it was evident how much much better people could hit, even a stationary target. We have a competition for kids, once a year, where they can do a city wide match in Zurich, shooting with assault rifles over 300 m range. Anyone between 14 and 16 (now, even girls can attend and they often win) can attend. With the smaller calibre, scores went up despite the old SIG510 was a very good gun. You can hit more, and more often, producing a similarly enough result. Should convince anyone going for smaller caliber.

 

Edited September 22, 2019 by ZachariasX

[cardboard_killer]

22 minutes ago, ZachariasX said:

For the soldier, it is clear that the 5.5 mm is the better choice, as he can neutralize more soldiers than with 7.6 mm. Why? The faster bullet makes him hit more frequently and on top of that he can bring more ammo due to lighter rounds AND a lighter gun. he is more powerful due to two factirs. *)

 

There are a bunch of old curmudgeons here who still think our military should  use 7.62x51 instead. I suspect most also think the M2 .50cal was the perfect weapon for a WW2 a/c. Quite a few also think the 1911a2 pistol is far superior to the glock 17.

 

Sentiment blocks reality.

[LColony_Kong]

2 hours ago, cardboard_killer said:

 

There are a bunch of old curmudgeons here who still think our military should  use 7.62x51 instead. I suspect most also think the M2 .50cal was the perfect weapon for a WW2 a/c. Quite a few also think the 1911a2 pistol is far superior to the glock 17.

 

Sentiment blocks reality.

Thats odd because I dont think 7.62 or 1911a2 are better than the examples you mentioned. I despise sentiment. If there is anything cancerous about the sim/airplane/gun/tank/grog community, it is the infatuation with pop-opinions and weapons and gear that get placed on a pedestal or committed to the trash heap.

 

[Sublime]

I havent seen anyone bring up one point:

Lets pit a P47 vs a Tempest.  The tempest has the 4 20s etc. HOWEVER the ammo is quite limited - especially for air to ground! 2 passes and its done for the tempest.

I feel this could be an important factor as well..

[LColony_Kong]

4 hours ago, JtD said:

Thank you for the polite tone you keep using. It makes your points much more valid.

 

 

Fair enough.

5 hours ago, Lord_Flashheart said:

With Hispano APIII kind of ammunition, the difference is extreme - APIII being capable of penetrating two inches of armour at 400 yards. And that's indeed sufficient to successfully attack the 30mm armour of Pz IV's. Wasn't used on a general basis, though, because German tanks weren't that common and the RAF went with the SAP&HEI round.

Going back to this I want to note that as you yourself pointed out, this round was not generally used, precisely because it was not the main target. Both of which are points which reduced the utility vs tanks.

 

Additionally the other 20mm rounds available would have been far less effective:

4 hours ago, JtD said:

You need some time on target, as not every round you fire is a hit. In particular when firing at a moving target with possible partical cover from several hundred meters out. It is a fact, that not everytime someone fired .50's from aircraft at a vehicle they scored dozens of hits. Not every vehicle got destroyed when it was strafed, in particular when it was defended and when there were several of them. Many of them were just damaged, starting with two simple holes in the canvas. I don't know where you take the certainty from claiming otherwise.

Yes you do. Which is why its better to have more ammo and a denser/wider beaten zone. However, given the patterns of these guns bursts, it is just as unlikely that you only get one hit as it is you hit with every single round. If you hit at all, you are likely to hit with multiple rounds. And you are more likely to hit "at all" with the 50s. And if you miss, you have more ammo to try again.

 

Additionally you guys are wildly overestimating the destructive nature of a 20mm round with explosive filler in ww2. A single 20mm hit hitting a random part of the vehicle as very likely not to kill the vehicle, just like a single 50 would not. A single 20mm to the engine or the crew cabin is only slightly more likely to kill the vehicle outright. It is not a bloody mortar round.

 

The most likely scenario for any burst from either gun system that finds its target at all, dozens of rounds to hit. Not one round. Not all of them.

[Ehret]

4 hours ago, Bremspropeller said:

Mobilzed Heer would have sich fine toys as a multi-barrel 20mm Flak gun they'd use for ground-air and gound-gound.

Heer would also not have to carry around a useless BMG.

 

WOULD is the correct world, indeed. Most of the Heer were on foot and horse drawn. Most Heer soldiers were carrying WW1 era rifles when US troops had M1 Garands as the standard issue. What else? Average age of Heer soldiers gone higher and higher relative to Allies as war progressed. At the end who it was? Old men and fanatics from HJ.

 

4 hours ago, Bremspropeller said:

But not becuse of the allmighty cal 50, but because the other side ran out of gas and pilots.

The Fw 190 is about half the volume and half the max TOW of the late P-47, yet it has a superior firepower.

 

Again... excuses because "they ran out of something". You can not say that LW's pilots were getting shot left and right? P-47s pilots had loss ratio only 0.7 per cent per mission and achieved an aerial kill ratio of 4.6:1 in ETO. It seems that "the superior" firepower didn't do much for the LW's plight.

 

4 hours ago, Bremspropeller said:

Writing that 8x50 cal is devastating is funny, because you need precisely that - eight - to make a comparable impact at the target as less than half the number of 20mm guns would do.

 

That's true but you should mention that many one engine Axis fighters didn't carry that many 20mm guns. The ones with heavier armament were handicapped and much easier pickings for Allied fighters. And what is really funny is that LW's fighter were equip with "peashooters" as well and only a pair at that. Why is it when Allied fighter carry a battery of 6-8 HMGs that's so inefficient but when Axis fighters carry just HMG (if not rifle caliber MG) pair and one 20mm cannon then it's so perfect?

[sevenless]

2 minutes ago, Ehret said:

 It seems that "the superior" firepower didn't do much for the LW's plight.

 

This is correct. The reason for this is numerical superiority and abysmal training of the german pilots. The human factor is decisive here.

[LColony_Kong]

1 minute ago, sevenless said:

 

This is correct. The reason for this is numerical superiority and abysmal training of the german pilots. The human factor is decisive here.

Except tactically the Germans were not out numbered, especially not during big week or during the first half of 1944 when the luftwaffe really took its hammering. The relay system meant that the few fighter groups actually capable of going into Germany were spread out and never there all at once. In actual combat, the Germans had the numbers advantage, especially early on. The idea they lost due mainly due to being out numbered only even makes half sense if your just counting the number of planes each air force had.

[Ehret]

3 hours ago, cardboard_killer said:

There are a bunch of old curmudgeons here who still think our military should  use 7.62x51 instead. I suspect most also think the M2 .50cal was the perfect weapon for a WW2 a/c. Quite a few also think the 1911a2 pistol is far superior to the glock 17.

 

Sentiment blocks reality.

 

History is that Allied fighters managed pretty good K/D ratios and achieved air supremacy at the end. Whatever excuses you may come with don't change that heavy loses were inflicted in the air to the Axis and bulk of them were done using the standard US 6-8x 0.50"s.

[cardboard_killer]

8 minutes ago, Ehret said:

Whatever excuses you may come with

 

Excuses for what?

[sevenless]

30 minutes ago, Lord_Flashheart said:

Except tactically the Germans were not out numbered, especially not during big week or during the first half of 1944 when the luftwaffe really took its hammering. The relay system meant that the few fighter groups actually capable of going into Germany were spread out and never there all at once. In actual combat, the Germans had the numbers advantage, especially early on. The idea they lost due mainly due to being out numbered only even makes half sense if your just counting the number of planes each air force had.

 

Nope, the turning point in the ETO was in the middle of 1943 when the 8th AF started to cover their bombers with fighters as you can see from the graphs below. Big Week in 2/44 only accelerated that effect. From Q4/1943 on the germans lost the battle of attrition in the air. The results were more an more untrained and inexperienced pilots in the air serving as cannon-fodder for the well trained RAF and USAAF fighter pilots. Local tactical superiority in one place didn´t help when the GAF as a whole wasn´t able to replace the human losses with adequately trained pilots.

 

 

Edited September 22, 2019 by sevenless

[Ehret]

36 minutes ago, cardboard_killer said:

Excuses for what?

 

The usual Axis running out "something" like fuel, material, manpower, time and so on.

 

BTW greatest firepower won't matter if you can not hit the target. Unless you were one of the great aces it was really, really hard. It's a different era with many enhancement but you can see a guy struggling to land a hit with twin (ADEN or relative) 30mm cannons on maneuvering fighter even if it's badly outmatched.

 

If you have that game and the P-51D and something with nose mounted cannons at cycling rate about 3000rpm you can do a simple experiment. Make mission with AI F-5E or Mig-15 flying straight at about 500km/h and try it shoot from dead six. Start with plane with nose mounted cannons then switch to the P-51D which has harmonization pattern for in-wing guns. The difference is startling... it's so much easier to score hits with the P-51D. They won't be anywhere as lethal but it's so easy to land them repeatably. With nose mounted 20-30mm it takes a small imprecision to make bullets fly over or under target's fuselage or wings. Not so in the P-51D - you have huge allowable margin for aiming and for firing time.

 

The question then is - how you would equip fighters to allow your pool of mediocre pilots to perform with known reliability? Would you prefer to obliterate a target once 10 sorties or be able to (almost) every time to make the enemy break (a mission kill) thus reliably cover your wing-men?

24 minutes ago, sevenless said:

 

Nope, the turning point in the ETO was in the middle of 1943 when the 8th AF started to cover their bombers with fighters as you can see from the graphs below. Big Week in 2/44 only accelerated that effect. From Q4/1943 on the germans lost the battle of attrition in the air. The results were more an more untrained and inexperienced pilots in the air serving as cannon-fodder for the well trained RAF and USAAF fighter pilots. Local tactical superiority in one place didn´t help when the GAF as a whole wasn´t able to replace the human losses with adequately trained pilots.

 

 

 

That's strategic metrics; locally it could look differently. Because the LW's was defending over own territory they could pull more sorties per every fighter per day, too.

 

Even if you will carry the "outnumbered" excuse whose fault it was?

Edited September 22, 2019 by Ehret

[cardboard_killer]

1 minute ago, Ehret said:

The usual Axis running out "something" like fuel, material, manpower, time and so on.

 

Excusing Axis failures? I celebrate Axis failures. I just wish it hadn't taken so many good men and women so long to stop the fascists. Part of that wish is that the US had armed itself with better weapons. Believe it or not, the Allies did not fight a mistake free war, and pointing out mistakes is not pro-fascism.

 

And facts are so lopsided in the issue of 20mm over .50cal as to make your argument turn to personal attacks on me as a fascist apologist.