Soviet Tank Destroyers

Part of the issue is knowledge of the Eastern front.

Most westerners will complain that they fitted 76.2mm guns to their standard and heavy tanks when they had much better guns to use, like 76.2mm AA guns and 85mm AA guns and even 57mm high velocity anti tank guns.

The thing is that modern wargames give a very skewed view of what was actually happening... at the start of the war the Germans had similar 76.2mm guns and new 50mm high velocity anti armour guns which were both plenty of fire power for taking on T-26s and BT series tanks... in fact you would say the 75mm gun of the Panther would be massive overkill if there weren't T-34s and KV-1s around the place.

The real issue was the lighter tanks disappeared from the battlefield while the better tanks got better so for the start of the war till they came up against the Panther the Russians didn't really need a specialist anti tank gun and the one they did have... the 45mms in wide spread service were good enough... they didn't even bother mass producing the 57mm high velocity guns... there were some fitted to T-34s but in combat in the western front the vast majority of uses of tanks was against other light tanks and against infantry positions where penetration wasn't critical and often a decent HE round was rather more important.

The 57mm gun which is not the same as the 57mm gun being revived in their new air defence vehicles in the form of the Au-220 turrets in the 2S38 vehicles... the new AA gun round is 57 x 347mm SR, the anti armour round was a more powerful 57 x 480mmR rimmed round, and it had very good penetration at useful ranges, but that penetration reduced with distance because of the light weight of the projectile... because of its small calibre.

It had better penetration performance over distances it could hit the target, but lack of shell weight meant the HE round was much less effective.

There is a lot of talk about the Shermans and their 75mm guns and the 76mm guns... ironically often the crews preferred the older guns with less penetration because they were smaller and had more HE which was more effective on soft targets.... and the fabled 17 pounder that so many wax lyrical about don't mention it is so inaccurate they didn't hit anything at more than 500m, which meant you had to get up close... which was not so easy with the later german tanks having bigger longer ranged guns.

The Soviets didn't really use tank destroyers much as such, they tended to put bigger guns in obsolete vehicle chassis that would operate behind the front line of tanks shooting ahead at strong targets like buildings and enemy tanks... vehicles like the SU-152 and later ISU-152 are good examples... they learned pretty quickly that a KV-2 was worse than useless and the loss of the turret traverse resulted in a better vehicle with the really big guns.

Certainly the Su-76 was very widely produced and the ISU-122 was widely used for direct fire support as well, but the upgrading of the tank guns to 85mm and then to 122mm calibre meant tank destroyers became a little redundant.

Their tank guns always had decent HE rounds... they didn't widely use guns purely optimised for anti armour use... nothing like the Panthers 75mm gun.... even the 100mm gun of the Su-100 had a reasonable HE round and was named "Fu*^ing end to everything" by its crews... the Germans treated it with a lot of respect.

Their raw tactics were pretty standard and pretty effective... every gun fired at enemy tanks till either was destroyed...

Their standard artillery included some very good 76.2mm guns, there 85mm AA gun (rough equivalent to the German 88mm, in fact many captured guns were rebored to 88mm when the captured 85mm ammo ran out...)... then it came down to the choice of the next calibre production capacity and HE performance led to the 122mm being chosen over the better penetrating 100mm gun.

Ironically in the post war period when the VDV wanted a light mobile vehicle that could kill armour used in enemy rear areas they went for the ASU-57... and over time when that became obsolete they upgraded to an ASU-85... but over time advancements in tank armour led to a combination of ATGMs and then 2S25M Sprut being used with its 125mm gun is probably their ultimate tank destroyers.

The fact is that the Germans only made about 1,600 Tiger Is and only about 6,000 Panthers and some were deployed to the western front too... so most of the time the 76.2mm gun was overkill... and at the start of the war the 57mm was a brand new calibre for which no ammo had been made yet.

By the time a heavier calibre was shown to be needed the 85mm gun did not penetrate as much armour at close range but it retained its armour penetration performance to much greater ranges and had a much better HE round.

Early testing of the 57mm armour piercing rounds showed they simply punched clean neat holes through enemy lighter tanks without doing a lot of damage except on the way through... 76.2mm rounds did rather more damage...

But then they had idiots in positions of power, for instance the person who approved the Nagant revolver rejected models whose chambers opened to allow all seven rounds to be ejected at once after firing because they thought it would lead to problems keeping units supplied with ammo, so the Nagant revolver they adopted has a loading gate so you load one round at a time and eject shell cases one at a time too.

Before the winter war the Soviets had the rather good PPS-40 which was not widely deployed because it used too much ammo too quickly... no surprise that fighting the Fins in forests using bolt action rifles and them using SMGs was a little costly in men...

But these ideas and problems led to changes and improvements...

Yeah in the early WW2 period a 45mm gun was more than enough.

It had the advantage of being light enough to be moved around the battlefield, and unlike other small calibre high velocity rounds on the time it actually had a good HE shell so it was used right to the end of the war as a sort of direct fire mortar for smashing bunkers and lighter vehicles and firing positions in buildings.

For every tank on the battlefield there are hundreds of lighter vehicles that support operations, so there were plenty of targets.

The Soviets started the war with more tanks than the rest of the world combined, but that is a little deceiving... the T-26 was in service in enormous numbers but was an awful very early design. It was essentially a modification of european vehicles, though the european vehicle it was based on either had a machine gun in the turret or a light 37mm gun, so the Soviet vehicle with a machine gun and a high velocity 45mm gun was actually very well armed for the time... but the armour was thin and mechanically they were a lot of work to keep operational... that is why they disappeared fairly quickly and they were not widely used by the Germans when captured... I seem to recall some were used as police vehicles in occupied areas, but the Germans didn't love the vehicle and use it as much as they could... like they did with the 76.2mm artillery and 120mm mortars they captured.

The German anti tank vehicle was a response to lots and lots and lots of Soviet tanks... the first lot were thinly armoured but they rapidly got better and better, and German tank production didn't expand at the same rate... so they cannibalised captured vehicles... another reason the battle at Stalingrad and Kursk were so important... they couldn't recover their lost tanks or tanks of the enemy, while the Soviets could recover vehicles and return them to service.

The Su-76 was a similar emergency solution which put a larger gun on a redundant light tank chassis.

Not quite as cheap as a towed gun with a truck to drag it around the battlefield, it was able to be produced in useful numbers and they could keep up with the rest of the forces... it was literally mobile direct fire artillery...

The T-34 75mm gun wasn't reliable enough against it and the Tiger's 88mm could easily outrange it. So the Soviets basically took a T-43 turret and put it into the T-34 to make the T-34-85.

But the new turret was also much bigger and had better arrangement so the commander was the commander and the gunner was the gunner and the loader was the loader... no distractions for the commander having to load the gun. The gun was also rather good... it was based on an AA gun and really was their 88 Flak gun equivalent.

There were constant complaints that the KV-1 heavy tank (which would be a medium tank in most other armies by weight) had the same gun as the T-34 medium tank, so things like the KV-85 were developed but as the T-34 was also going to get an 85mm gun they decided that the heavy tank would have to go even bigger so they looked at 100mm and 122mm guns... the latter won because it was a calibre and ammo that was already in mass production for other weapons.

At this point I would point out that all calibres are not equal... a 76.2mm gun and a 76mm gun and a 75mm gun can have wildly different performances because they use totally different rounds. The 88mm gun of the Tiger I is a very powerful gun, but the 88mm of the Tiger II is much more powerful... it is not the same ammo despite being the same calibre.

A 122mm artillery shell from an SU-122 which is based on the T-34 chassis and has a short stub 122mm gun with a 122mm calibre round was a relatively small round... not much propellent. In comparison the 122mm gun of the IS-3 was enormous and had a huge propellent case and launched a heavy projectile at much much higher speeds.

It is like the difference between a 223 rifle round and a .22LR round... very similar calibre, but one is a low velocity small round for hunting rabbits at short ranges less than about 80m and the other is a very high velocity round for shooting people at 200-400m range depending on the rifle used.

What I was trying to say was that the 122mm shells were already in mass production even though the new gun used a much bigger propellent case to achieve its improved performance. Having lots of projectiles ready makes it easier and fast to mass produce the new ammo... you just make extra...

Tank destroyers were an interesting compromise made in WW2 for expediency's sake. But as you can see they fell out of favor and don't exist any more. Some were designed and built in the 1950s but they were typically put into storage and not used in practice. A turreted tank is simply more versatile. Open top vehicles are highly susceptible to artillery.

Conceptually they have been replaced by missile carrying vehicles, but the Sprut is also technically an example of a tank destroyer for use by amphibious and airborne forces.

Whether that was a good idea from logistics point of view is another matter, but fact is that Germany had limited domestic production capabilities, so they utilized not just captured anti-tank guns, but also entire tanks, trucks, armored cars... not just tanks, entire Germany army of the time was a giant Frankenstein's monster.

Very true. In some cases, like the high velocity 85mm guns they captured... when they ran out of captured ammo they rebored the guns and used 88mm ammo in them. In the case of 120mm mortars they put the weapons and ammo into production themselves. Things like Tokarev pistols and PPSh-41 SMGs they already used the 7.62x25mm calibre ammo.

But even then notice these are all turreted vehicles. The closest thing to a WW2 tank destroyer in the Cold War era would be something like the German Kanonenjagdpanzer or the Swedish S-Tank.

American tank destroyers had turrets... often open topped, but still turrets... vehicles like the M18 etc...

Yeah now that is a different vehicle which was not specifically designed in a limited resource or time constraint scenario.

The Su-85 and Su-100 were tank destroyers... their guns were optimised for use against enemy tanks at extended ranges, and their ability to provide fire support against enemy positions was limited...

Germany modified what they had to make tank destroyers but that was because of the position they were in at the time.

From what I understand the M18 Hellcat was developed mostly for political reasons in the US military. The cavalry branch decided they needed dedicated tank destroyers. To an obsessive degree. I suppose it was much lighter than the M4 Sherman so it could have helped with strategic lift. The cost was about the same and the gun also the same.

In many ways you could say the limited HE performance of the high velocity 75mm gun on the Panther made it a type of tank destroyer... because the Germans were faced with an endless stream of T-34s and KVs they had to deal with so a more general purpose vehicle like a Panzer IV with a long 76mm gun needed a dedicated TD to operate with it.

GarryB wrote:The fact is that the Germans only made about 1,600 Tiger Is and only about 6,000 Panthers and some were deployed to the western front too... so most of the time the 76.2mm gun was overkill... and at the start of the war the 57mm was a brand new calibre for which no ammo had been made yet.

By the time a heavier calibre was shown to be needed the 85mm gun did not penetrate as much armour at close range but it retained its armour penetration performance to much greater ranges and had a much better HE round.

Early testing of the 57mm armour piercing rounds showed they simply punched clean neat holes through enemy lighter tanks without doing a lot of damage except on the way through... 76.2mm rounds did rather more damage...

There was one more thing you have not addressed.
ZiS-2 and 4, because we are talking that gun, was extremely expensive to produce, and required a very complex, time-consuming, and precise production process.
A barrel itself was approx. 4m long, and needed extra efforts for both the production stands, worker skills, and additional quality check at each process.
The 57x480 mm ammo was a new addition to the Soviet inventory either, and in order to retain its penetration performances, it used a quite sophisticated round as well, just from the beginning with UBR-271. With tungsten carbide core, making it expensive, again.
All of that made it not suitable for a mass war the Soviets faced in the 1941, so the efforts were redirected for much easier to produce, and having much more secondary use ZiS-3.
The fact that all the rumors about German supertanks turned to be not true till the 1943 didn't help here ...