Recoil operation

Recoil operation is one of the firearm actions used in automatic firearms.

It uses the recoil of the barrel to cycle the action. This requires the barrel to move back a short distance, before the bolt is unlocked. The movement of the barrel is then arrested, and the bolt continues to move to the rear. There is a further distinction between short recoil and long recoil operation.

(Short) recoil operation is common in pistols.

The MG-42 machine gun and its descendant the MG-3 use recoil together with roller locking. The Maxim gun and the Barrett_M82A1 heavy sniper rifle are also examples of recoil operation.