Monday, 2 October 2017

Lend Lease Impressions: 57 mm M1 Anti-tank Gun

"57 mm M1 Anti-tank Gun

American 57 mm M1 Anti-tank Gun

The gun has a semiautomatic vertical sliding breech, the semiautomatic mechanism is a mechanical type. The mount has split trails. The gun fires one-piece armour piercing shot (without explosive filler).

The following is a comparison of main characteristics of the American 57 mm anti-tank gun and our 45 mm anti-tank gun mod. 1942, 57 mm IS-1 anti-tank gun, and 76 mm ZIS-3 gun.

Characteristics
45 mm anti-tank gun mod. 1942
American 57 mm M1 gun
57 mm IS-1 anti-tank gun
76 mm ZIS-3 divisional gun
Mass in battle position, kg
570
1140
1120
1120
Shell mass, kg
1.43
2.85
3.14
6.5
Muzzle velocity, m/s
870
815
900
655
Penetration of a K-2400 armour plate at 90 degrees




100 meters
70 mm
78 mm
98 mm
75 mm
300 meters
65 mm
70 mm
91 mm
72 mm
500 meters
61 mm
63 mm
86 mm
69 mm
1000 meters
51 mm
48 mm
71 mm
61 mm

The American 57 mm anti-tank gun weighs about as much as our 57 mm IS-1 anti-tank gun, but the penetration is significantly less than that of our gun, and is only somewhat higher than that of the 45 mm anti-tank gun mod. 1942, which weighs almost half as much as the American gun.

As a result of trials performed with this gun, it was established that the main drawback is the dependence of the recoil mechanisms on the temperature of the hydraulic fluid (in winter conditions). Until the fluid is heated, the gun will not return to its original position after recoil.

The gun has insufficient clearance, the diameter of the wheels is too small, and the suspension is rigid, which lowers the qualities of the gun on maneuver, especially when pushing it across the battlefield with the force of the crew. 

The design of the gun does not satisfy modern requirements for anti-tank guns, and makes it suitable for stationary defenses only.

57 mm armour piercing tracer shot

Ammunition for the 57 mm M1 anti-tank gun

57 mm armour piercing tracer shot, American make
The results of trials were satisfactory. The shot is a modern design, but it is inferior to domestic 57 mm armour piercing shells due to the higher muzzle velocity of the latter.

11 comments:

  1. Some US units equipped with these guns in 1944-45 started essentially abandoning them and using bazookas instead. Obviously the bazooka was much worse in many ways, but it was highly portable and more versatile.

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  2. Amazing how good the 76mm ZIS-3 was really....about the same weight, and performance as the British/US 57mm in the AT role, but, it fired a very useful HE round also so it was much more useful as a general purpose gun.

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  3. Wait, the AP Shot M70, that has the same weight as the round tested here, almost the same speed (853m/s instead of the listed 815m/s) has a LOT more penetration when it was tested by the 'western' allies themselfs... So my question is what ammo did they get? or what went wrong in testing?

    Since the American gun should compare to the russian 57 and the british QF 6-pounder (That is nearly identical to the american one, barrel length of the American was better until the Brits started using the Mark IV gun) was in service till 1951 with the army, and it was even used in the Korean war...

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    Replies
    1. Different testing standards. Soviet penetration figures are lower for all foreign guns, across the board.

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    2. The British repeatedly upgraded the 6pdr's ammunition. By March 1944, APDS rounds were in service. The US didn't manufacture anything beyond the base AP nature and sometimes omitted the charge from even that. Units in the field obtained the good stuff whenever they could. I wonder which natures the USSR tried?

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  4. The Soviet 57mm had a MUCH longer gun tube than the US/British 57mm. I don't know the ammo details but I would think the Soviet gun would have far better performance.

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    Replies
    1. The IS-1, the gun in this table, had a shortened barrel.

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    2. I am not familair with the IS-1 57mm....I assume the performance of the ZIS-2 57mm is much better though.

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    3. The Canadians made a souped up 6 pdr in 43, the "Canuck" a much longer barreled higher velocity version. Sadly while finished it was just kept in testing until after the war, The Canadians only wanted to adopt it if the British did and they were unsure/dragging their feet over it the entire time.

      APCBC 3.23 kg fired at about 950-1005 m/s
      Canadian CR 1.93 kg fired at about 1250 m/s

      APCBC https://i.imgur.com/il5JTfU.jpg
      CR https://i.imgur.com/3WUnkfZ.jpg

      Sabot could be fired as well but I don't really have much data on that.


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    4. There was also the 6-pdr David, firing 2-pdr projectiles as the subcaliber penetrator. Suffered the same fate, unfortunately.

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    5. Yea :/

      Back before the 17 pdr was placed in the Sherman the UK did request all data on the Canuck as a possible alternative to mount instead of the 17 pdr. In the end it hinged on the British wanting to know the performance of the APCBC round compared to the 17 pdr, it was also stated as they did not have enough supply of tungsten to provide enough rounds for all weapons so APCR performance was less interesting to them. Canada responded that they had in excess of 2,000,000 lbs in stock at the time...

      The original requirements for the gun are interesting as well, "requirement for this project is to defeat the 100mm spaced plate armour of the PzKw VI tank attacked at 30 deg to normal at ranges 800 to 1000 yards"

      I guess during this period they were expecting Tigers to appear with spaced design like on the III and IV.

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