Most Effective Soviet Tank Gun

[Pips]

In the latter stages of WWI the Soviets produced some very capable tanks armed with hard hitting guns.

The IS-2 had the powerful A-19 122mm gun, although that gun was better because of it's high explosive shell rather than it's ability to defeat late war German tanks.
The T-34/85 was equipped with either the D-5T or the 85 mm Zi-S gun. Good, but unable to defeat tanks such as the Jadgpanther or the King Tiger.
The Su 100 had the very effective 100mm D-10s. To my mind this was arguably the most effective anti-tank gun that the Soviets mounted on either a tank or tank destroyer. While it still couldn't defeat either the Jagdpanther or the King Tiger front on, it could penetrate the Panther or Tiger 1 from the front.

According to "Soviet Tanks and Combat Vehicles of World War Two" by Steven Zaloga, the D-10s gun was capable of penetrating 85mm armour sloped at 30 degrees at 1000m. And in the book "Armour in Profile #21 SU 85 and SU 100 Tank Destroyer", Colonel E. F. Offord, it's claimed that the D-10s could penetrate 160mm armour at 1000m.

Interested in what folks think.

[Twix]

In order to get a meaningful answer to your question ("What is the most effective Soviet tank gun?"), you have to keep in mind the different approaches the Germans and Soviets had to tank design. The Germans preferred to upgrade their tanks as often as they could with the aim of gaining a technological advantage over their opponent. This philosophy failed and ultimately led to disappointing results on the battlefield. The numerous differences in the different models of tanks they fielded made training, operation, and repair a logistical nightmare. Although late-war German tank guns (those on the Tiger and Panther) could penetrate Soviet tank armor with ease, they were fielded in such relatively low numbers that their edge in power was essentially a wasted effort.

The Soviet approach to tank design was, in many respects, a complete 180 degree turn from the German one. All aspects of their tanks were designed at the bare minimum level at which reliable and straightforward performance was guaranteed. This approach ensured that mass production of tanks could be sustained and allowed the Soviets to enjoy an overwhelming numerical superiority in tanks in virtually every engagement. The effect of this approach to tank design produced tank guns which met Soviet doctrinal, and tactical requirements albeit at the loss of penetrating power. While T-34/85s could not penetrate Panther and Tiger armor, the fact that there were so many of them and so few of the Tigers/Panthers eliminated the German edge in firepower.

So in short: Instead of looking at which Soviet tank guns could and could not penetrate German tanks and judging them solely based on this, you must instead look at how well they satisfied the overarching goals of the military leadership and warfare doctrine.

[randwick]

.
the 122 mm choice for the JS2 is typical of this , while the 100mm was very good there were problems with the ammunition supply
while the 122 was plentiful and fit for the purpose IE an assault tank to be used for break through operation
most targets would be strong points and artillery ,
there were very few tigers around and the JS2 could cope with them well enough

[ain92]

First of all, IS-2 has D-25T, not an A-19 (although they have the same ballistics), a modification of 85 mm D-5T gun that was inconvenient for T-34-85 turret. D-10T and D-10S were further development of D-5 with new counter-recoil mechanisms.

The penetrating abilities measured in different countries should not be compared because the piercing criteria differs, so the German numbers are usually smaller than English and US ones.

[ChristopherPerrien]

Hands down ,The D-10. That gun is still being used . While not quite as effective as the 122mm on a single round basis, the D-10 used a cased round, whereas the 122mm had a bagged propellant charge, which greatly reduced the rate of fire , plus all the other attendant difficulties that go with having 2 piece ammo in a tank .

[ain92]

Hello, Christopher.
Well, the guns that are used in later modifications of T-55 are much more accurate, stabilized and have bore evacuators etc.
And there're documents that in cramped turret of IS-2 rates of fire were almost the same. It was more convenient for the loader to carry separate cartridge case (AFAIK bags weren't used) and shell then one long fixed shot.

[ChristopherPerrien]

I loaded tanks, besides shooting them , driving them, sleeping on them, for a few years. Loading a bag charge instead of a single piece cased round halves your rate of fire, simple as that, No excuses and no reason to think otherwise. And in reality will work worse than 1/2 because of the sheer ergonomics of loading a tank round under stress. Which were even less acknowledged and and understood in WWII , than they are today.

100-120mm is understood as the upper limit of the size of a tank round, otherwise it will be two piece, and that don't work in a "any" tank. Really the Soviet 100mm D-10 AT round was the progenitor of every round used now in any tank in the world, and also is to the upper limit to the size of a round a tank crew can handle effectively.

[ChristopherPerrien]

I loaded tanks, besides shooting them , driving them, sleeping on them, for a few years. Loading a bag charge instead of a single piece cased round halves your rate of fire, simple as that, No excuses and no reason to think otherwise. And in reality will work worse than 1/2 because of the sheer ergonomics of loading a tank round under stress. Which were even less acknowledged and and understood in WWII , than they are today.

100-120mm is understood as the upper limit of the size of a tank round, otherwise it will be two piece, and that don't work in a "any" tank. Really the Soviet 100mm D-10 AT round was the progenitor of every round used now in any tank in the world, and also is to the upper limit to the size of a round a tank crew can handle effectively.

[ain92]

The topic "Why IS-2 was armed with 122 mm gun but not the 100 mm?" was actively discussed about 10 years ago. Unfortunately I don't have enough time to translate all the ideas but you can use auto-translators for http://ru.wikipedia.org/wiki/%C8%D1-2#. ... 1.82.D0.B0 and http://tank.uw.ru/archive/perepiska/doc3.

[Clive Mortimore]

I loaded tanks, besides shooting them , driving them, sleeping on them, for a few years. Loading a bag charge instead of a single piece cased round halves your rate of fire, simple as that, No excuses and no reason to think otherwise. And in reality will work worse than 1/2 because of the sheer ergonomics of loading a tank round under stress. Which were even less acknowledged and and understood in WWII , than they are today.

100-120mm is understood as the upper limit of the size of a tank round, otherwise it will be two piece, and that don't work in a "any" tank. Really the Soviet 100mm D-10 AT round was the progenitor of every round used now in any tank in the world, and also is to the upper limit to the size of a round a tank crew can handle effectively.

The British 120mm in the Chieftain and Challenger is bag charged and as far as I am aware does not have a detrimental effect on the rate of fire compared to similar calibred tanks using a fixed round. It does mean you get the brew on earlier as you do not have a tank full of brass to empty out.