Linked from
The 11 pages that link to Recoil operation, each with the reason it gives.
Machine gunRelated: Some machine guns use recoil to extract a spent case and chamber the next round.
RecoilBroader topic: Some firearms harness the rearward movement that recoil produces.
Maxim gunNarrower topic: The barrel and bolt recoil together, powering the Maxim gun’s firing cycle.
Automatic firearmRelated: Some automatic firearms use recoil to power each loading and firing cycle.
AutocannonRelated: Many autocannon actions harness recoil to cycle after each shell is fired.