Usage: Production tanks: no. Experimental tanks: KV-1S, JS-85. Simultaneously with the work on the 85mm tank gun S-18, the TsAKB developed yet another variant of the 85mm tank gun. This weapon, given the nomenclature S-31, was designed for mounting on the heavy tanks KV-1S and JS, for which reason two separate variants were created — one with a standard ballistic of the 85mm Anti-Aircraft Gun (muzzle velocity of 790–800 m/s), the other with a higher ballistic (muzzle velocity of 920–950 m/s). The model with the higher muzzle velocity was developed for mounting in the JS-4 tank in place of the 107mm ZIS-6. Manufacture and trials conducted by Factory #92. In comparison to the S-18, this weapon was simpler and better made. However this weapon, with its higher muzzle velocity, required a new round with a larger case to be developed. Because of poor communications and a delay of the decision, they began to fulfill this order only at the middle of October, 1943, which had been planned to be fulfilled by October 1, 1943. Due to this problem, all of the research on the high-velocity 85mm Tank Gun S-31 was put aside. In the summer of 1943, a comparative trials were conducted on four separate tanks: JS-85 with S-18 gun and JS-85 with D-5 Tank Gun, KV-1S with S-18 tank gun and KV-1S with D-5 tank gun. Trials demonstrated that more effectiveness could be wrung out of the D-5 gun, and it was this, which was mounted on the final versions. S-31 GUN SPECIFICATION Parameter | Value | Calibre, mm | 85 | Bore lenght, clb | ? | Weight of pendulous elements, kg | ? | Weight of recoil elements, kg | ? | Normal recoil length, mm | ? | Max. recoil length, mm | ? | Ammunition | fixed | Ballistic | 85mm Anti-Aircraft Gun Model 1939 | Practical ROF, shot/min. | ? | AMMUNITION FOR THE D-5, S-18, S-31, S-53, ZIS-S-53 GUNS SHELL | PROJECTILE | PROPELLANT CHARGE | Index | Weight, kg | Index | Weight, kg | Length, clb | Weight of a charge, gram | Fuse | Index | Weight, kg | HIGH EXPLOSIVE, FRAGMENTATION | UO-365 | 15.95 | O-365 | 9.2 | 3.4 | 0.646 | T-5 | G-365 | 2.48 | UO-365K | 16.3 | O-365K | 9.54 | 3.4 | 0.646 | KTM-1, KTM-1-U | G-365 | 2.5 | UO-365KV | 14.95 | O-365KV | 9.54 | 4.1 | 0.67 | V-429, KTM-1-U, KTM-1, KTMZ-1-U, KTMZ-1, MG-N | G-365 | 2.6 | UO-365G | 14.95 | O-365G | 9.54 | 4.1 | 0.741 | KTM-1-O', KTM-1, KTMZ-1-U, KTMZ-1, MG-N | G-365 | 1.5–1.8 | UO-367* | 14.95 | O-367 | 9.54 | 4 | 0.703–0.741 | KTM-1 | G-365 | 1.5–1.8 | UO-367A* | 14.95 | O-367A** | 9.54 | 4.2 | 0.67 | KTM-1-U, KTM-1, MG-N | G-365 | 1.5–1.8 | UO-367AV* | 14.95 | O-367AV** | 9.54 | 4.1 | 0.67 | V-429, KTM-1-U, KTM-1, MG-N | G-365 | 1.5–1.8 | O'I^-367AG* | 14.95 | O-367AG** | 9.54 | 4.1 | 0.67 | KTM-1-U, KTM-1, MG-N | G-365 | 1.5–1.8 | ARMOR PIERCING | UBR-365 | 16 | BR-365 | 9.2 | 4.3 | 0.164 | MD-5, MD-7 | G-365 | 2.48–2.6 | UBR-365K | 16 | BR-365K | 9.2 | 3.1 | 0.048 | MD-8 | G-365 | 2.48–2.6 | UBR-367* | 16 | BR-367 | 9.2 | 3.64 | 0.044 | MD-8, DBR-2 | G-365 | 2.63 | ARMOR PIERCING SUB-CALIBER (HVAP) | UBR-365P | 11.42 | BR-365P | 4.99 | 3 | N/A | N/A | G-365 | 2.5–2.85 | UBR-367P* | 11.72 | BR-367P | 5.3 | 3 | N/A | N/A | G-365 | 2.5 | UPBR-367* | 11.72 | PBR-367 | 5.3 | 3 | N/A | N/A | G-365 | 2.5 | SHAPED-CHARGE ANTI-TANK (HEAT) | UBK-367* | 14.95 | BK-367 (BK-367M) | 9.25 | 7 | 0.994 | GKN | G-365 | 1.3 | ZBK2* (ZBK2M) | 14.95 | BK2**** | 7.351 | 7 | 0.935 | GPV-1, GPV-2 | G-365 | 1.3 | CANISTER AND SHRAPNEL | n/a | INCENDIARY | n/a | SMOKE | UD-1 | 16.3 | D-2 | 9.54 | 4.1 | - | KTM-1-U | G-365 | 2.6 | UD-2 | 14.95 | D-2 | 9.54 | 4.1 | - | KTM-1-U | G-365 | 1.5–1.8 | UD-367 | 15.65 | D-3672 | 10.07 | 4 | - | KTM-2 | G-365 | 1.5–1.8 | * Developed after the end of WW2; ** Case made of cast iron; *** Ballisctic capped; **** Fin-stabilised. Sources: «Artillerijskoye Vooruzhevie Sovetskikh Tankov 1940-1945» Armada-Vertical, #4, 1999 |