The two were mismatched; the NR-23 was a rapid-fire weapon with relatively low explosive power, while the N-37 was extremely powerful, typically able to destroy a bomber with a single hit, but with very a low firing rate which made it unsuited to firing at manoeuvring targets like fighters.

It was essentially an enlarged version of the NR-23 using the same short recoil mechanism firing a new 400 gram 30 mm round that was roughly twice the mass of the earlier NR-23 and slightly less than half that of the N-37.

While not capable of destroying a bomber in a single hit, it made up for this by improving the firing rate to 900 cycles per minute, beyond that of the NR-23.

This demanded the use of a muzzle brake with an integrated flame damper to prevent airframe damage from its firing.

This often required small sections of stainless steel to be fitted to the wing skinning to protect it.