Monday, 15 July 2013

Soviet 57 mm Guns

The Red Army, in its anticipation of hilariously over-armoured enemy tanks realized that the penetration of the F-34 gun was lacking. That is why, in 1941, Grabin's 57 mm ZiS-2 gun was adapted to the T-34 (and, in theory, T-34M). A shorter version of the ZiS-2 gun was named ZiS-4, and put into the T-34. The resulting tank, currently known to many as "T-34-57", appeared in documents as "T-34 with 57 mm gun", "T-34 with ZiS-4", "T-34 tank destroyer", or any combination of the above. Since the F-34 was already capable of defeating any enemy armour at 2000 meters, not very many of these tanks were made. CAMD RF 38-11355-323 lists 10 such tanks being sent from factory #183 to Vladimir to form the 21st Tank Brigade.

ZiS-4 57 mm gun model 1941

T-34 model 1941 with a 57 mm gun

In 1942, the Tiger hit the battlefield, and GABTU suddenly remembered this thing they had going pre-war. The 57 mm gun program was revived. A new and improved ZiS-4 was designed to fit the new and improved T-34 model 1942 turret.

ZiS-4 57 mm gun model 1943

T-34 model 1942 with a 57 mm gun

Four experimental T-34 tanks were built in June-July of 1943. However, at that point, work on 85 mm tank guns began, so no one was quite sure what to do with these odd ducks. CAMD RF 38-11344-1755 tells of their uninteresting fate:

"According to the ciphertext from Major-General comrade Vershinin, four T-34 tanks with the ZiS-4 artillery system were sent to the Gorohovets proving grounds, where, after trials, one tank was sent to factory #92, and the rest sent back to factory #183.
Please advise what to do with these tanks."

Notice how the new gun is still "ZiS-4", and not "ZiS-4M". 

The tests at Gorohovets were concluded on September 15th. The above document is dated October 11th. The T-34 armed with the longer S-54 76 mm gun was tested at Gorohovets around the same time. At this point, the first T-34-85 was already being built by factory #183, so new 57 and 76 mm artillery systems for the T-34 were discontinued. A project to stick the ZiS-4s already produced into SU-76es was also launched, but didn't really go anywhere. 

However, despite the 57 mm gun never quite making it on a tank, it was quite handy in its ZiS-2 form as towed artillery. Here's how it performed against the Tiger, from CAMD RF 38-11377-12:

"Target: side. Distance: 800 meters. Result: penetration, 110 mm in diameter. A fragment, 190 mm by 210 mm broke off on the inside. The welding seam connecting the side and rear plates burst in an area 500 mm in length.
Target: side. Distance: 1000 meters. Result: penetration, 110 mm entrance, 140 mm exit. Fragment broke off on the inside, 140 mm by 110 mm."

The gun is more than capable of taking out the Tiger from the side. Let's try the turret.

"Target: commander's cupola. Distance: 1000 meters. Result: penetration, breach 85 mm by 75 mm. The cupola was torn off.
Target: turret. Distance: 1450 meters. Result: dent, 110 mm in diameter, 70 mm deep. A 20 mm cracked bump formed on the inside.
Target: turret. Distance: 1450 meters. Result: dent 49 mm deep, 125 mm in diameter, with a jagged surface. On the inside, a 15 mm bump.
Target: turret. Distance: 1450 meters. Result: dent, 110 mm in diameter, 15 mm deep."

The gun is less capable against the turret (although they probably should have closed in a bit after the first few bounces). Shooting at the cupola is an effective tactic.

"Target: upper front plate. Distance: 500 meters. Result: insignificant indent, the shell ricocheted into the driver's vision port.
Target: upper front plate. Distance: 500 meters. Result: dent, 90 mm in diameter, 20 mm deep. The welding seam is destroyed throughout its entire length. 
Target: lower front plate. Distance: 500 meters. Result: dent, 120 mm in diameter, 35 mm deep. Two 70 mm cracks in the dent. The welding seam is destroyed on a length of 500 mm."

Seems like the front is a tough nut to crack. The welding seams are failing one by one, as usual. With enough hits, the front plate is bound to fall off!

Conclusions: "As a result of shooting at the Tiger tank with the domestic 57 mm gun, it has been established:
a) The AP shell penetrates the 82 mm thick side at 1000 meters.
b) The AP shell does not penetrate the 100 mm thick front at 500 meters."

Not fantastic results, but not surprising. The results are better than the British 6-pounder gun of the same caliber, at least.

The Tiger II test document does not mention the 57 mm gun, but that doesn't mean it couldn't take one out. A Tiger II with numerous breaches from a 57 mm AT gun was displayed during an exhibition of captured vehicles.

The text reads: "Armour: 100 mm" on the turret and "armour: 85 mm" on the hull. Two arrows on the turret point at breaches, and are labeled "the armour was penetrated by a subcaliber 57 mm shell from an anti-tank gun".

1 comment:

  1. What are some of the bullets used in the test ?

    BR-271? BR-271K?