Nudelman-Suranov NS-37

The Nudelman-Suranov NS-37 (Russian: Нудельман - Суранов НС-37) was a 37-millimetre (1.5 in) aircraft cannon, which replaced the unreliable Shpitalny Sh-37 gun. Large caliber was planned to allow destruction of both ground targets (including armoured ones) and planes (ability to shoot down a bomber with a single hit).

Nudelman—Suranov NS-37
Il-2 with NS-37 cannon in under-wing pods
Type	Autocannon
Place of origin	Soviet Union
Service history
In service	1943–1945
Used by	Soviet Union
Wars	World War II
Production history
Designer	A. E. Nudelman and A. Suranov
Designed	1941
Manufacturer	Izhmash
Produced	1942–1945
No. built	6833
Specifications
Mass	170/160 kg (with motor/wing mount)
Length	3.41 m
Barrel length	2.3 m
Width	21.5 cm
Height	41.5 cm
Cartridge	37×198 mm
Barrels	1
Action	short recoil
Rate of fire	240–260 rpm
Muzzle velocity	900 m/s (HE, HEI-T), 880 m/s (AP-T)
Feed system	Belt

Developed by A. E. Nudelman and A. Suranov from OKB-16 Construction Bureau from 1941, it was tested at the front in 1943 and subsequently ordered into production, which lasted until 1945. It was used on the LaGG-3 and Yak-9T fighter planes (mounted between the vee of the engine, in motornaya pushka mounts) and Il-2 ground attack planes (in underwing pods).

Although the heavy round offered large firepower, the relatively low rate of fire and heavy recoil made hitting targets difficult. While pilots were trained to fire short bursts, on light aircraft only the first shot was truly aimed. Additionally, penetration of medium and heavy tanks' top armour was possible only at high angles (above 40 degrees), which was hard to achieve in battle conditions. For these reasons it was soon replaced in 1946 by the N-37 autocannon, which used a lighter 37×155 mm round.