using a rotating cylindrical drum having a camming groove (F41F1/10 takes precedence)

Full Title

Auxiliary mechanisms for bringing the breech-block or bolt or the barrel to the starting position before automatic firing; Drives for externally-powered guns; Remote-controlled gun chargers > Drives for externally-powered guns, i.e. drives for moving the breech-block or bolt by an external force during automatic firing > using a rotating cylindrical drum having a camming groove (F41F1/10 takes precedence)