Anti-tank gun caliber 76.2 / 57 mm C-40 (1946-1948)
Device and construction
The lower part (carriage) for the new gun is taken from the 1944 “ZIS-S-8” anti-tank gun of the year 85mm caliber. In the carriage make small changes. Due to its conical shape, the barrel had a 76.2 mm caliber for the most part (breech) and an 57mm caliber for a smaller portion (muzzle). The length of the cylindrical barrel was 5.4 meters. The charging chamber for the new gun was taken from an anti-aircraft gun caliber 85mm sample 1939 of the year. After the chamber, the threaded conical part of the 76.2mm caliber began with a length of 3.2 meter. She had a 32 rifling constant gradient (22 caliber). The muzzle part received a nozzle with a cylindrical channel. The area of the conical smooth nozzle had a length of 51 centimeter, a portion of the cylindrical nozzle 59 centimeters. The tool receives a wedge vertical shutter and mechanical copy-type semi-automatics. Homing angles are (-5 + 30) degrees vertically, (± 25) degrees horizontally. The C-40 doesn’t have a weapon rifle; Suspension of the wheel travel torsion, the maximum transportation speed on the equipped road to 50 km / h. Total weight C-40 - 1824 kilogram. The unfolding / folding of the instrument in time was about 60 seconds. Firing speed up to 20 / min.
Ammunition anti-tank guns C-40
The main ammunition for the guns were selected armor-piercing sabot and high-explosive fragmentation incendiary-tracer shells. A piercing armor-piercing projectile had a length of 84 centimeters and a mass of 6.3 kilograms. The armor-piercing core (25mm) weighed a little over half a kilogram. The weight of the powder mass 2.94 kilogram. All this provided the projectile with a high flight speed (initial 1330 m / s), a sufficient effective firing range of up to 1500 meters and incredible armor penetration for a given caliber:
- at a distance of 0.5 kilometer projectile penetrated when hit for 285mm armor protection;
- at a distance of 1 kilometer projectile penetrated when hit for 230mm armor protection;
- at a distance of 1.5 kilometer projectile penetrated when hit for 140mm armor protection.
The OFZT ammunition had a length of 89 centimeters and a mass of 9.3 kilograms. The mass of the projectile is 4.2 kilogram, the mass of the explosive projectile is 105 grams. The mass of the propellant charge is 1.3 kilogram, the flight speed is up to 783 m / s.
Comparison of C-40 and PaK 41
The Soviet analogue 7,5, see the cannon PAK-41 (Grabin's system) superior to the trophy model in ballistic and armor penetration characteristics, for comparison: at a distance of 0.5 kilometers the German gun pierced the armor to 200mm (C-40 to 285mm).
The fate of the anti-tank gun C-40
The built prototype of the C-40 gun was successfully shot out at the factory and field tests that took place in the 1947 year. Accuracy and armor penetration of sub-caliber armor-piercing ammunition was higher than that of the tested ZN-57 anti-tank gun 2mm. But OFZT ammunition was inferior to fragmentation ammunition (ZIS-2) in terms of effectiveness (fragmentation action). In the 1948 year, the C-40 ground test continues. But, unfortunately, due to the low survivability and high complexity of the manufacturing technology of the barrel, the C-40 anti-tank gun was not put into service with regimental artillery.
Information sources:
http://raigap.livejournal.com/152496.html
http://forum.guns.ru/forum/42/000009.html
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