Its full official name is 45-mm anti-tank gun model 1942 (M-42) (Russian: 45-мм противотанковая пушка образца 1942 года (М-42)).

The gun received a longer barrel (20 calibers more than the previous one, so it was a 45 mm/L66), shells with more powerful cartridges, and a thicker shield (7 mm instead of 4.5 mm), but of hinged construction as a need for reduced profile, requiring crews to kneel while serving the weapon.

In 1943, due to its insufficient anti-armor capabilities against new German tanks such as the Tiger, Panther and Panzer IV Ausf H, the M-42 was partially replaced in mass production by the more powerful 57 mm ZiS-2 anti-tank gun.

The M-42 remained in production however, as it was quite effective against lighter vehicles and could pierce the side armour of the Panther and Panzer IV Ausf H. Fragmentation shells and canister shot gave the gun some anti-personnel capability.

On the 24th of January 2025 a video appeared of an M-42 gun being destroyed by a Ukrainian drone operator in the occupied Russian territory in the province of Kursk.