Updated tank gun comparison

[Soren]

Here's an updated WW2 tank gun comparison.

I've looked through US German manuals, modern day data and so on to make sure everything is 100% accurate.

12.8cm PaK44 L/55

Projectile weight: 28.3 kg (PzGr.43 APCBC)
Sectional Density: 1.727
Muzzle Velocity: 880 m/s
Total Kinetic Energy: 10957 KJ
Kinetic Energy pr. cm^2: 85.15 KJ

8.8cm KwK43 L/71

Projectile weight: 10.4 kg (PzGr.39/43 APCBC)
Sectional Density: 1.342
Muzzle Velocity: 1000 m/s
Total Kinetic Energy: 5200 KJ
Kinetic Energy pr. cm^2: 85.49 KJ

10cm D-10

Projectile weight: 15.88 kg (BR-412D APBC)
Sectional Denisty: 1.588
Muzzle velocity: 887 m/s
Total Kinetic Energy: 6246 KJ
Kinetic Energy pr. cm^2: 79.52 KJ

7.5cm KwK42 L/70

Projectile weight: 7.2 kg (PzGr.39/42 APCBC)
Sectional Density: 1.280
Muzzle Velocity: 925 m/s
Total Kinetic Energy: 3080 KJ
Kinetic Energy pr. cm^2: 69.7 KJ

7.62cm 17pdr

Projectile weight: 7.7 kg (Solid shot AP)
Sectional Density: 1.326
Muzzle Velocity: 883 m/s
Total Kinetic Energy: 3001 KJ
Kinetic Energy pr. cm^2: 65.8 KJ

12.2cm D-25T L/43

Projectile weight: 25 kg (BR-471B APC)
Sectional Density: 1.679
Muzzle Velocity: 780 m/s
Total Kinetic Energy: 7605 KJ
Kinetic Energy pr. cm^2: 65 KJ

9.0cm M3 L/53

Projectile Weight: 10.94 kg (M82 APBC)
Sectional Density: 1.350
Muzzle Velocity: 853 m/s
Total Kinetic Energy: 3980 KJ
Kinetic Energy pr. cm^2: 62.56 KJ

8.8cm KwK36 L/56

Projectile weight: 10.2 kg (PzGr.39-1 APCBC)
Sectional Density: 1.317
Muzzle Velocity: 773 m/s
Total Kinetic Energy: 3107 KJ
Kinetic Energy pr. cm^2: 51.09 KJ

8.5cm D-5T L/54

Projectile weight: 9.2 kg (BR-365 APBC)
Sectional Density: 1.273
Muzzle Velocity: 792 m/s
Total Kinetic Energy: 2885 KJ
Kinetic Energy pr. cm^2: 50.84 KJ

7.6cm M1 L/55

Projectile weight: 7.0 kg (M62 APCBC)
Sectional Density: 1.211
Muzzle Velocity: 792 m/s
Total Kinetic Energy: 2195 KJ
Kinetic Energy pr. cm^2: 48.38 KJ

7.5cm KwK40 L/48

Projectile weight: 6.8 kg (PzGr.39 APCBC)
Sectional Density: 1.208
Muzzle Velocity: 790 m/s
Total Kinetic Energy: 2122 KJ
Kinetic Energy pr. cm^2: 48.03 KJ

 

[fastmongrel]

Hi Soren thanks for that info very interesting comparison but could you tell me what the sectional density means I think I understand all the other figures but that has got me stumped.

I also noted that the 76.2 mm 17 pounder and the 7.5cm KwK42 are remarkably similar in all figures obviously the German and British designers were thinking along the same lines.

 

[Soren]

Sectional density in very rough terms pretty much refers to the projectile's ability to penetrate a certain object at a certain speed. The higher the SD the higher the penetrative ability pr. amount of speed.

 

[hartmann]

Hello Soren.

Thanks a lot for the data on sectional density and KE/cm2. It is an excellent work ¡¡

Does the sectional density correlates with capability to remain intact upon penetration?

Thanks a lot and my best regards

 

[vikingBerserker]

Nice data Soren!

 

[Matt308]

Sectional density in very rough terms pretty much refers to the projectile's ability to penetrate a certain object at a certain speed. The higher the SD the higher the penetrative ability pr. amount of speed.

While Soren is correct, this is somewhat of an arbitrary number used for calculation of ballistic coefficient and gross ascertion of performance. This number in an of itself is not conclusive to the efficiency of a particular round's ability to travel farther, with less drift or ability to penetrate an objective media. I am unfamiliar with the use and validity of this parameter applied to ballistics beyond small arms.

 

[Soren]

You're completely right Matt, there are MANY other factors which affect the penetrative ability of a AP projectile, and one of the most important is the steel quality and composition.

Much more important to penetration performance is the pressure/energy pr. surface area generated, which is shown as the KE pr. cm^2.

 

[Soren]

Btw guys, you're welcome to provide similar data on other guns if you wish. In the end we might get a sticky made out of it

 

[timshatz]

Impressive post Soren.

Any numbers on armor penetration? I realize it would be tricky, differing plates and all that, but it would be interesting.

Was impressed by the kinetic energy by the 12.8cm round. That sucker hits with some impact. Even makes the 88 look relatively docile.

 

[lesofprimus]

Agree with u Tim in a big way.... 10957 KJ tops the list....

Thanks for the info Soren....

 

[Soren]

Thank you guys, you're most welcome.

Tim,

I could add penetration stats but like you rightly pointed out it would get abit confusing seeing that every country tested their guns against different quality and different BHN plates. So instead I decided to add the energy spread pr. surface area, which looks past steel quality, form factor, test critierias etc etc and just provides you with the raw penetration power that the gun offers. As you can see the 8.8cm KwK43 tops the list, barely superceding the 12.8cm PaK44, but I must point out that after just 1,000 m it has reversed and the PaK44 is slightly ahead. By 2,000 m the difference in the penetration performance established in German tests between the 12.8cm PaK44 and 8.8cm KwK was a mere 16 mm (132mm vs 148mm) in favor of the PaK44, so they were close.

You also see why the Soviets should have opted for the 10cm D-10 instead of the 12.2cm D-25T, the D-10 was an extrememly powerful gun with a lot of potential. With an identic projectile it was only slightly behind the 8.8cm KwK43 in penetration performance at all ranges, but the larger HE shell would've made up for that.

 

[timshatz]

I was kicking it around in my head last night and realized the 12.8cm gun was the same size but longer than the US Navy's 5" 38 that was used on US destoyers as a primary weapon during the war. Round weights about the same. 50Lb or so.

At that point, the penetration of the round is impressive but so is the explosive effect. One of those things go off against the side of a tank will probably disable if not destroy it.

Honkin' big round.

 

[Stitch]

I was kicking it around in my head last night and realized the 12.8cm gun was the same size but longer than the US Navy's 5" 38 that was used on US destoyers as a primary weapon during the war. Round weights about the same. 50Lb or so.

At that point, the penetration of the round is impressive but so is the explosive effect. One of those things go off against the side of a tank will probably disable if not destroy it.

Honkin' big round.

No kidding!

It's also interesting to realize that the MBT's of today don't even have guns this big (though their MV is much higher), so the PaK44 wouldn't be too out of place even today.

 

[m kenny]

In 1949 a Churchill with 235mm of applique armour was fired at from 100yds by a German 128mmm gun.
2 AP hits on the hull left gouges and cracks but did not penetrate. One hit on the turret knocked it off but did not penetrate. 2 rabbits placed in cages inside the tank survived and showed no ill effects!

 

[plan_D]

Nice list there, Soren. Good to see all information collected and easily referenced.

m_kenny, the Churchill was a bit of a beast when it came to absorbing rounds, eh? Unfortunately if your turrets come off, your battle is pretty much over.

 

[delcyros]

For me the most important figures given above are sec. density and kinetic energy per cm^2. The latter does provide a rough indication of initial penetration performance (at the muzzle, everything else beeing equal), the former shows how well the projectile will keep it´s penetration performance at distance (actually APCBC will be better than APC due to the aerodynamic windscreen). Energy retention is heavily linked to sec. density and form factor.
projectile properties are not taken into account but it still gives a reasonable idea about the gun itselfe.

 

[DerAdlerIstGelandet]

In 1949 a Churchill with 235mm of applique armour was fired at from 100yds by a German 128mmm gun.
2 AP hits on the hull left gouges and cracks but did not penetrate. One hit on the turret knocked it off but did not penetrate. 2 rabbits placed in cages inside the tank survived and showed no ill effects!

Who cares, it was still knocked out of action...

Nice picture though.

 

[plan_D]

I agree, the picture's cool. But I have to also mention...rabbits...the physical make-up of a rabbit is ...well, a lot different from that of a human. Given the size of a human in such a confined space, I'm thinking physical damage would have been more likely especially if the freakin' turret fell off.

 

[DerAdlerIstGelandet]

I agree, the picture's cool. But I have to also mention...rabbits...the physical make-up of a rabbit is ...well, a lot different from that of a human. Given the size of a human in such a confined space, I'm thinking physical damage would have been more likely especially if the freakin' turret fell off.

I agree...

 

[Soren]

I'm not sure what it is m_kenny is trying to prove cause I've got the Aberdeen results for the 12.8cm PaK44 and it easily outperformed any other gun tested in terms of penetration performance, only the 8.8cm KwK43 came close. At Aberdeen the PaK44 punched through 267mm of vertical 240 BHN RHA armour at 100 yards with the regular APC round, the KwK43 managed 232mm with the regular APCBC round and a phenomenal 304mm with the APCR round!

I'd like to know where m_kenny's picture is from though and how he can be sure that the description is right. I mean seeing that a round supposedly knocked the turret off I'd atleast expect to see a freaking dent! I'd actually like to see some evidence of hits on the tank at all.