Best tank gun for year

[Vincenzo]

as the manual tell if the troops are in the open or are unarmoured vehicles the mg are enough you do not need to fire HE shell for do damage, if they have a little protection is more usefull the 20 kwk that the 2 pdr, not that the 20 kwk is the ideal weapon but i think is more usefull of 2 pdr in that situation, obviously vs a tank or an other armoured vehicle the 2 pdr is clearly superior

 

[Shortround6]

Thing is that an AT gun is a threat to the tank if the AT gun can be swung (traversed) onto the firing tanks position. It is also a threat to any friendly units in front of it. The AT gun/s need to be neutralized before this can happen. This was the big failing of the British tanks using 2pdr and 6pdr guns, NO HE to engage AT guns. And the German manual is saying to use the 20mm gun ONLY on the front aspect of the AT gun (against the armor shield)?

It seems as if both the 20mm gun (as used in the MK II tank, the armored cars may/probably have had HE ammunition), and the 2pdr were pretty much in the same position/situation in this case.

 

[Vincenzo]

again i'm not agree
both need to fire to the shield (imho i don't think that a small shell like a 20mm with a normal HE load can be used like a artillery and put out of service the ATG with the splinters)
the 2 kwk can fire more rounds in the same time
penetrate the shield the 2 kwk shell explode that of 2 pdr no

 

[Shortround6]

A single 20mm round cannot act like a bigger artillery shell but multiple 20mm rounds?

Here is where Mr. Bender confuses the effectiveness of modern 20mm guns (or post war guns) with the 20mm KwK. The post war German gun could fire about 30 shells in two seconds. Not only machine gun like even if the shells do not explode but shells hitting the ground, structures, large trees/branches and parts of the gun itself (trail legs, etc) can explode. The WW II German TANK guns fired at about 4.5 and 8 rounds a second but had that 10 round magazine. After 2 seconds everybody in the target area will have gone to ground and be much harder to hit with either mg bullets or 20mm shells. A 20mm Flakvierling can fire 80 rounds in 2 1/2 seconds which explains a large part of it's effectiveness. Cutting the number of rounds fired to 1/8th and using AP instead of HE and the effectiveness becomes ?????

20mm HE shells may work against the shield on an AT gun and blow a hole in it. 20mm AP rounds will go through it. However a 2pr projectile going though the shield turns 4 times as much metal from the shield into splinters as a 20mm projectile. Getting hits on the shield is a real problem as the AT Guns are so much smaller than tanks. Getting hits on the barrel or recoil system is pretty much a matter of luck.

Trying to hit barrel/recoil cylinder at 600-900 meters?

Both guns (20mm Kwk and 2pdr) are pretty ineffective against dug in or positioned AT guns, or soft targets in general.

Again, perhaps the armored cars with their high angle mounts had HE ammo that could be used against ground targets too but it doesn't seem like the MK II tanks had it.

we could get into the shoulda/woulda game (British screwed themselves many times over with their obsession with cheap ammo) But as used both guns had similar limitations in target effectiveness. Germans masked it much better because they seldom used MK II tanks alone in units larger than platoons after the very early part of the war so there were usually some other tanks in the company that could fire HE, unlike the British who had too few HE firing tanks for far too long.

 

[Vincenzo]

you gain miss my point (already writed in my n° 18 post)
20mm is autocannon so for 1 pdr round fired we have some 20mm shell fired
20mm has aphe shell so after penetration they explode
so it's true that the one 2 pdr round put 4 times more metal inside respect ad 1 20mm shell but this explode and is not one 20mm shell but a few

 

[Shortround6]

We are arguing about bad and really bad

The early 20mm KwK had a rather poor rate of fire (280rpm) and while German fuses were often better than British ones, fuses on AP rounds functioning properly after penetration was always a bit iffy. How many feet behind the shield does the shell detonate after penetration? kind of depends of impact velocity (range to target), thickness of shield, angle of shield, manufacturing tolerance of fuse, etc. This is assuming the fuse functioned at all after penetration.

The First British projectile for the 2pdr was an APHE but they gave up on it because of high number of fuse failures and the fact that the solid shot penetrated more armor. Like I said the German fuses were better but far from perfect.

The MK II tank is going to get off 10 shots in 1.2-2.5 seconds depending on gun and holding the trigger until the magazine is empty. This is assuming the recoil doesn't throw the aim off. Then there is a pause of several seconds (2,3,5, more?) while the commander, gunner, loader (all the same guy) takes out the old magazine, gets a new one and fits it into the gun.
Yes, the gun was an "auto-loader" but many people are using the same 'effectiveness' as the ground mount single barrel AA gun or other "auto-loaders" with larger feed systems and/or dedicated loaders in the crew operating in less confined spaces. Just like the towed 2pdr AT gun was rated at 22-25rpm but the 2pdr gun in the Valentine turret pictured earlier in the thread is going to need divine intervention to even come close to that.

The Armored car guns may do better. But the MK II tank was NOT one of these with the advantage of a closed turret

They may use the same ammo but the target effect is a lot different.

 

[Vincenzo]

actually i never thinked that a Pz II is a flak gun in a armoured turret and never thinked to a long burst mode fire
if the 20mm firing in semiauto mode (like a pistol) probably it fired (almost) 4 shell for one 2 pdr round so also if only 2 explode we had same ammount of metal inside plus 2 small explosion, i think fuses for AT shell are very fast the tank were small, early war very small, so probably very few feet

 

[Shortround6]

Just for comparisons sake a British No 36 Mills bomb grenade weighed 369g and contained about 92g of HE of various types depending on availability. which is much less than the German Stick grenade.
A German 37MM Flak projectile weighing 635g contained about 24g of PETN wax and the 37mm AT/Tank gun HE shell weighed 610g and had 25g pressed TNT with a large tracer. The AP projectile weighed 680g and had 13g PETN wax.
The 50mm AT/tank gun had a HE projectile with 165g of pressed TNT in a 1.78kg projectile and the 2.05KG AP projectile had 25g PETN wax/
The 75mm AT/tank guns used a HE projectile with 640g of amatol in a 5.8kg projectile and the APHE weighed 6.8kg and had a 16g burster of cyclonite/wax.

The 37mm and 50mm HE rounds were somewhat useful although each tank battalion had a company of 75mm armed tanks for close support ( a British battalion was lucky if it had 8 tanks total with HE firing guns).

The American 37mm AT/tank gun fired an HE projectile with 38.6g flaked TNT in a 730g projectile.
The American/British 75mm guns used an HE shell of 6.67kg with a 667g burster.

It is not impossible to take-out an anti-tank gun with 2-4 rounds of 20mm ammo weighing around 120g with a 3.6g burster but considering that most countries figured you really needed the 75mm guns to handle dug in guns and field fortifications the 20mm AP rounds really don't look very effective. Please note the Flakvierling could deliver about 480g of HE (9.6kg of shell weight) in about 2.5 seconds which may help account for it's reputation in ground combat. Apply dud rate as you see fit ( and everybodies 75mm guns had at least some duds,too).

Of course the MK II tank engaging an AT gun from the front is in the position of using whatever 20mm projectiles it has or using the co-ax gun on a target (the gun shield) that was designed to counter that exact weapon.

 

[Vincenzo]

the point is not that 2 cm kwk can do a good work v/s a ATG but that can do a better work of 2 pdr with its AP round
i think that all are agree that a 75mm gun HE shell is better and actually a 105mm HE shell is much better,