Best tank gun of WW2???

I notice you don't give the penetration for the M-304 round.

As far as naval penetrations go the US also speced for a larger off angle penetration I beleive. From what I've read this had a some lessening effect on their penetration at normal. Not at all sure how this affected the army guns and shells though. I have read that the Britts tested their guns with some wear while the US tended to use new guns. I'm not at all sure what the Germans did in this regard.

Then there's the question of how much penetration do you need? Is the best gun one that's "good enough" and lets the tank cary more rounds or one that's got a lot of over penetration?

Then if we are talking about the Maus how about the T-20 series?

 

The M304 was a HVAP (APCR) round, which wasn't in huge supply, plus it had its issues with performance against sloped armour and actual killing power once a penetration was achieved.

The Germans, British & US all tested their guns against 30 degree sloped plates as a std., the US Navy was no different in this respect, so there was no difference there.

The Germans, British & US also all tested relatively fresh guns. So again no difference there either.

The only difference between the three was the quality of the test plates and the penetration criteria used.

 

The gun needs to fit the vehicle, and the vehicle needs to fit the doctrine for the country.

The 7.5/L70, 17pdr and 77mm (Comet) allow for a vehicle with good mobility and range.

The bigger guns see trade offs on mobility (infrastructure, suspension etc) and range that makes it a more defensive weapon platform.

Unless you are thirteen and think Tiger II are cool, the massive vehicles are more one dimensional.

 

Well Tiger IIs and Maus were hardly in huge supply either. And you were talking about gun power with out defining it.

To say because they tested at the same angles there was no difference is making a lot more out of things than is warranted. It's pretty widely reported theat the US speced for it's naval shells to withstand impacts at greater obliquity than most other navies for one thing. For another look at this table:
http://www.navweaps.com/index_nathan/Armor_Penetration_of_USN_14in_Mark-16_Mod-4_AP.pdf
Note the testing at 35 degrees.

Again it's been widely stated that one of the reasons the US expected more out of the 76mm gun than they got is that the testing was all done with new guns where the British specefied a certain amount of wear on the guns for thier test. The implication is that there was a signficant difference. So I at least am not willing to accept your assurance without some supporting data.

Blanket statments like this are usually wrong so I at least tend to doubt them especially when data and references are lacking.

 

lwd I don't think anyone ever mentioned the Maus, which sported a 12.8cm gun btw. And there were many other vehicles that sported the 8.8cm L/71 gun than just the Tiger II, plus the fact that it was widely used as an AT gun. So not sure where you're heading with that comment?

You don't seem to understand that OB refers to impact angle and not target slope. The 16" guns of the Iowa class fired to out beyond 40,000 yards, at that range impact angles on fully vertical armour was over 45 degrees.

And what do you mean by widely reported? You found a single internet link lwd, one that doesn't even support your thesis, come on now.

But I can also post links:
USA Guns 90mm calibre

In short according to all the sources I have, including Hunnicut & Zaloga, ALL the US penetration tests were conducted against plates laid back 30 degrees from the vertical. Exactly the same as the Germans & British.

Not true, the reason the 76mm gun didn't perform as hoped was that the shells it fired featured far too soft a nose. And that is also the only reason.

Well all I can say is that of all the sources available on the matter it is made quite clear that the std. test procedure during US penetration trials was to fire against 30 degree sloped plates. In all my years of researching the matter 35 degree sloped plates are not mentioned even once. You are ofcourse welcome to believe in what'ever you want however. One thing is for sure though, the penetration figures I presented before, which are the official ones for the 90mm M3 gun, were conducted against 30 degree sloped plates at Aberdeen. That I do know.

Also I believe the pure physical kinetic energy of each gun as-well as the penetration results obtained at Aberdeen speak for themselves.

 

But how many of the other vehicles were tanks? The Maus certainly was although only in prototype. The US also had 105 armed tanks. It all depends on what you want to consider.

How the angle is achieved is rather imaterial as far as whether or not the shell penetrates and or breaks up.

You implied all testing was done at 0 and 30 degrees. I demonstrated that it was done at other and indeed greater angles. In this case all it takes is one link to prove that point. But again I was talking about the shell specifications rather than testing, although they would have to test to make sure the shells met the spec. But as for widely reported it is mentioned with reasonable frequency on most of the naval boards I'm on.

Indeed you can. And thanks for proving my point. Both the US 90mm guns mentioned there have rounds with greater pentration at ~1,000m than the German guns.

I just gave you one where the angle was 35 degrees.

Sorry that's not what I've read. Indeed while that may have been a factor in why they didn't perform up to their theoretical expected performance this would have little impact on peformance expected based on actual test.

Well I just gave you a source that mentions 35 degrees. 30 was probably the standard and the most often used at least by the army but that doesn't mean that other angle weren't tested and indeed I presented evidence that they were.

 

lwd, an impact angle at 35 degrees is not the same as shooting at a target laid back 30 degrees. How come you don't understand this?

The sheet you showed from www.navweaps.com does not show testing against targets laid back 35 degrees as you claim, it shows the impact angle of 16" shells at longe range penetration tests against vertical plates. Also as a Navy board member you should understand that at the ranges which the main guns of Battleships started firing at an impact angle of over 40 degrees was completely normal. An impact angle of 35 degress translates into about a 30 to 35km range, which is normal Navy weapons testing range. This doesn't have anything to do with target inclination however, which is where you are confused atm.

Fact is that the US Army & Navy std. was to test guns against either vertical or 30 degree sloped targets. For army guns not shooting much further than 2000 yards, the std. was to test against 30 degree inclined plates. These were the exact same standards as those used by the Germans & British.

First of all you shall know that the 90mm T15 gun wasn't ever used in combat during the war, and it fired two piece ammunition btw, just like the 12.8cm PaK44 L/55.

Also what do you mean by me supposedly proving any point of yours? What point would that be ? I think you need to look at the data again, while also taking into consideration the following:

1. The Germans tested their guns against higher quality plates
2. German criteria demanded that 2/3rds of the projectiles fired completely penetrated the plate. The US only demanded 50% to partially penetrate the plate.
3. Forget about HVAP rounds (M304), they were rare and lacked effectiveness. Look at APCBC or APC performance as these were the rounds used by both parties.

As a result the 8.8cm L/71 gun quite effortlessly outperformed the US 90mm gun in tests conducted at the Aberdeen Proving Grounds in the US.

Why is it you keep wanting to ignore these facts lwd?

Aberdeen data:

8.8cm KwK43 L/71 penetration performance against 240 BHN RHA vertical plates:
10.4 kg PzGr.39/43 APCBC
100m = 232mm
500m = 219mm
1,000m = 204mm
1,500m = 190mm
2,000m = 176mm
2,500m = 164mm
3,000m = 153mm

9.0cm M3 L/55 penetration performance against 240 BHN RHA vertical plates:
10.9 kg M82 Late APC
100m = 169mm
500m = 164mm
1,000m = 151mm
1,500m = 138mm
2,000m = 127mm
2,500m = 115mm
3,000m = 104mm

7.5cm KwK42 L/70 penetration performance against 240 BHN RHA vertical plates:
7.2 kg PzGr.39/42 APCBC
100m = 185mm
500m = 168mm
1,000m = 149mm
1,500m = 132mm
2,000m = 116mm
2,500m = 103mm
3,000m = 91mm

So as you can see the 8.8cm KwK/Pak43 L/71 performs far better than the 90mm M3 at any range (Naturally as the gun is far more powerful), and the 7.5cm KwK42 L/70 is superior up until 1,000m.

The data is from Lorrin R. Bird & Robert D. Livingston's book WW2 Armour & Gunnery and is based on trials conducted at the Aberdeen Proving Grounds after the war.

 

I'm not quite sure why I was being so dense on that point.

However as you point out the angle is not 30 degrees. Nor is it for a 16" gun for htat matter or particularly long range. Looking at the velocities and the table at:
USA 14"/50 (35.6 cm) Mark 7, Mark 11 and Mark B
It looks to be at somewhere between 10Kyards and 15Kyards although the angles would correspond more to 30 Kyards vs verticle plates. In any case the implication is clear that not all ap test were done at 30 degree inclination of the plate.

Source please. These may indeed be the standards for some purposes but I'm pretty sure the navy also specified that the shells had to survive certain angles of impact which were different from those of other nations. I'll try to find a source.

Wasn't it? I seem to recall that a couple of Pershings so equipped were deployed to Europe and fired a few rounds but could easily be wrong on that.

That by some criteria such as armor penetration the US guns were better.

Now you are imposing different criteria. No such limitations (ie availability or even combat use were imposed at the beginning of this thread).

The only facts I'm ignoring is your assumptions as to what we were discussing and that due in part to your not specefying them ahead of time.

For instance if you are talking best tank gun why concentrate on AP rounds? In US service anyway 70% of the rounds fired were HE.

 

Perhaps it will help if I sumarize my stance on this topic.

There is no such thing as a best tank gun of WWII. There may not even be a best tank gun for any one nation during the war.

Some would argue some flavor of the 88 was the best. However would it have been any use at all for the Japanese? They lacked the tanks to carry and for the most part even the terreign to make a tank carrying one useful. A less extreme example would be for the Germans facing the Soviets AP performance was probably more critical than it was for US tanks whose primary threats were AT guns, mines, and later in the war infantry. Indeed the US developed a couple of tanks (T-27 and T-28 I think) that carried 105mm guns as opposed to the 105mm howitsers carried by some Shermans. However they simply didn't see the utilty of these tanks. Transportion issues alone pretty much limited them. So while comparative capability of the guns, tanks, planes, or whatever may be quire interesting declaring one "the best" unless a very restricted and narrow defintion of best is used is for the most part an exercise in futility and fundamantally flawed.

 

lwd,

My sources on the matter have been stated, Hunnicutt, Zaloga, Jentz, Livingston & Bird amongst others.

And according to all the sources I have, and have read through the years, the std. practice by the US Navy & Army was to fire at either vertical or 30 degree inclined plates. And this was exactly the same as was done by the Germans & British. It quite simply wasn't done any other way.

The sheet you linked at www.navweaps.com shows results with 14" (not 16" that was my mistake) guns against vertical plates where the impact angle was 35 degrees because of range and projectile trajectory. It's a std. Navy penetration performance test sheet showing normal impact angles for long range Navy tests. And taking the 14" guns trajectory and final velocity of the Mk.16 projectile into consideration the impact angle reveals that the range to the target was around 30,000 to 31,000 yards. Again typical Navy style long range test.

But thats not the truth lwd, you're ignoring the facts put right infront you. As proven in actual tests the German guns routinely performed much better than US & British guns, especially in Allied tests. And I've already shown you the actual real life test results as-well as explained to you differences in criteria and test plate quality which caused the differences you see.

But I will quote directly from Livingston this time:
"By the end of the war the US had tested German projectiles and found them significantly better than ours, against our own and British plates. As their penetration data for their own guns showed, the Germans were able to make VERY resistant plates through to the end of the war for their own test programs."

Added to what I've already explained about criteria & test plate quality, Livingston here explains that German projectiles also were better than the ones made in US & Britain. He later goes on to explain how German projectiles were made harder and with more tensile strength than Allied ones, which along with the stricter German test criterias and test plate quality is the explanation behind the much better performance exhibited by German guns in Allied tests as compared to the German's own trials.

And this has already been mentioned:

2. German criteria demanded that 2/3rds of the projectiles fired completely penetrated the plate. The US only demanded 50% to partially penetrate the plate.

And again the Aberdeen data, which btw mentions the late M82 projectile and not the more numerous early soft nosed type used throughout the Normandy campaign:

8.8cm KwK43 L/71
Projectile: 10.4 kg PzGr.39/43 APCBC
Muzzle Velocity: 1,000 + m/s
Target: Vertical 240 BHN Rolled Homogenous Armour plates
100m = 232mm
500m = 219mm
1,000m = 204mm
1,500m = 190mm
2,000m = 176mm
2,500m = 164mm
3,000m = 153mm

9.0cm M3 L/55
Projectile: 10.9 kg M82 APC (Late)
Muzzle Velocity: 853 m/s
Target: Vertical 240 BHN Rolled Homogenous Armour plates
100m = 169mm
500m = 164mm
1,000m = 151mm
1,500m = 138mm
2,000m = 127mm
2,500m = 115mm
3,000m = 104mm

Now the above results are hardly suprising when we use our own sense of logic. While this is oversimplifying it in order to create better understanding one can ask oneself: What is more easily going to puncture my skin, a needle or a plastic bottle? That answer should come easily to anyone. It's all about pressure over surface area. Hence why modern tank guns fire long but very slender arrow like shots for penetrating armoured targets, the high caliber of the gun only being to ensure the capability of firing a powerful HE round. The more energy you can squeeze into a tighter area the better your penetration (same principle behind HVAP & APCR shots). And the most efficient way achieve higher energy is through an increase in speed.

Now then lets look at the guns here:

8.8cm KwK43 L/71 fires a 10.4 kg APCBC projectile at 1,000 + m/s, which translates into a total kinetic energy of over 5200 KJ. This force is concentrated over an area of 8.8cm in diameter, which equals a KE concentration of 85.49 KJ pr. cm^2. By comparison the 90mm M3 L/55 fires a 10.91 kg APC projectile at 853 m/s, wich translates into a total KE of 3980 KJ. Now thats 1220 KJ less than the KwK43 in raw energy transferred to the projetile alone, which is a huge difference in itself. On top of this the smaller force possessed by the 90mm projectile is dispersed over a larger area as-well, giving a KE concetration of 65.56 KJ pr. cm^2.

Thats a difference of 30.3% in energy concentration, and not surprisingly the difference in penetration between the two guns when the 90mm gun uses the improved late type M82 projectile is in the same area at 37.3%. The slight increase caused by the fact that the German gun fires a slightly harder and more durable projectile as explained by Livingston.

So aleast now we've established that physics and the actual test results walk hand in hand.

 

On the issue of superior German plates ,later on in the war the Germans had problems procuring chromium & nickel for armor having to substitute vanadium instead which made plates much weaker.

On the issue on which gun is better a person could make a very valid argument that the US 75mmM3 was a better weapon for say the Sherman then the 17pdr or 76mmM1A1 simply because it had far better HE. Most Shermans were knocked out by panzerfaust/bazooka's, mines , SP's and anti-tank guns. In fact Panzers only accounted for around 15% of Sherman kills along with the SP's accounting for around 22-25%. So better HE performance was more important in around 60% of the time a Sherman was knocked out. You also have to take into account how many infantry lives are saved by having better HE rather then maybe a better AP gun .

Now I'm not trying to say any one gun is better then the other but just that AP performance is not wholly the only or even best indicator which is the best.

 

Hi icky, this apparently only applied to tank armour, tanks such as the Panther & Tiger Ausf.B suffering from this. The plates used for testing purposes however were of higher quality then what was used anywhere else from the start of the war until its end in 1945, which the tests also show quite clearly. The Germans, and the British & US for that matter, would test each sample of plates before testing to make sure that quality met the demanded standard, if it didn't the plates were discarded, simple as that. This was also explained by Livingston.

 

Not picking on you but look at say tanks being used in the jungles of the Pacific a short barreled gun like the US 75mmM3 or one could say even better the 7.5cm/24 of the early MK IV's would probably be alot better then the long barreled 76mmM1A1's, 17 pdr's , 7.5cm/70's, Fak 8.8 cm or 8.8cm/71's simply because long barreled guns could be unyieldly in jungle conditions . In fact I think the Australians fielded a shortened Baby 25pdr for use in jungle conditions but that may have been a feature to reduce wieght but that is a field artillery issue.

Even sheer AP attributes may not tell the whole story if tank A has twice the armor of it's contemporary tank B along with a more powerful gun BUT that contemporary tank B can nevertheless penetrate the tank A's armor at most combat ranges does it really matter? Even the 75mmM3 could penetrate the Panther's side armor at quite long ranges. What about inferior AP guns in inferior armored turrets but very fast in traverse up against far better AP guns in more heavily armored but much slower traversing turrets? Superior AP weapons may mean far heavier weapons with such trade offf's.

 

88mm L/71 ?

 

I think the King Tiger is "cool"... can I be 13 again?

 

You're not exactly comparing apples to apples. The 7.5KwK L24 was basically the lIG18 (an infantry gun) converted to electric primer ignition. They did have AT rounds of questionable value but its main role was infantry support with HE & smoke.

 

Oh I understand fully but my point is in the Pacific jungle a shorter barreled gun with much inferior AP performance maybe more practical then a large high velocity tank killing gun.

 

"71" is the length in calibers of the barrel. I'm thinking the proper designation either Pak43 or Kwk 43 but correct me if I'm wrong.

 

Most people think the King Tiger is "cool". It was the most heavily armored tank of the war and had the most powerful gun ever put into a rotating turret during WW2, the fearsome 88mm KwK 43 L/71. Plus it looks awe inspiring with its thick sloping armor and huge gun.

 

Mmmm how about the 75mm gun on the panther? Better penetration than the 88mm.