Variable barrel camming system for firearm

A barrel with cam slot for a firearm, the barrel comprising:

• a tubular body defining a longitudinal axis;
• a muzzle end and a breech end defining a chamber for holding an ammunition cartridge;
• an axial bore extending between the breech and muzzle ends defining a projectile pathway;
• a camming lug protruding downward from the breech end of the barrel;
• and
• a multi-contoured cam slot formed in the camming lug and configured to slideably engage a cam pin, the cam slot including a rear end, a front end, a rear upper surface extending between rear and front ends, and a front lower cam track surface extending between the rear and front ends opposite the upper surface;
• the lower cam track surface having an undulating cam profile comprising a first concave surface, a second concave surface located forward of the first concave surface, and a convex protrusion arranged between the first and second concave cam surfaces.

A method for operating a firearm, the method comprising:

• providing a firearm including a longitudinal axis, a frame, a horizontally oriented slide supported by the frame in a sliding manner for rearward and forward reciprocating motion, a horizontally oriented barrel removably coupled to the slide and including a cam slot including an upper surface and an opposing lower cam track surface, and a cam pin fixedly disposed transversely in the frame;
• discharging the firearm;
• moving the slide and barrel rearward together in coupled relationship;
• moving the cam pin forward in the cam slot;
• slideably engaging the cam pin with an initial cam section of the lower cam track surface of the cam slot;
• slideably engaging the cam pin with an intermediate variable cam section of the lower cam track surface of the cam slot having an arcuately curved concave cam profile;
• rotating the barrel about the cam pin and uncoupling the barrel from the slide via engagement with the variable cam section;
• slideably engaging the cam pin with a final cam section of the lower cam track surface of the cam slot;
• disengaging the cam pin from the final cam section;
• slideably engaging the cam pin with a re-direction surface of the upper surface of the cam slot having an arcuately curved concave cam profile, the re-direction surface being disposed on an opposite side of the cam slot from the final cam section;
• and
• engaging a closed front end of the cam slot with the cam pin, wherein motion of the barrel is arrested.

A method for operating a firearm, the method comprising:

• providing a firearm including a longitudinal axis, a frame, a horizontally oriented slide supported by the frame in a sliding manner for rearward and forward reciprocating motion, a horizontally oriented barrel removably coupled to the slide and including a cam slot, and a cam pin fixedly disposed transversely in the frame;
• discharging the firearm;
• moving the slide and barrel rearward together in coupled relationship;
• moving the cam pin forward in the cam slot;
• slideably engaging the cam pin with an initial cam section of the cam slot;
• slideably engaging the cam pin with an intermediate variable cam section of the cam slot having an arcuately curved concave cam profile;
• rotating the barrel about the cam pin and uncoupling the barrel from the slide via engagement with the variable cam section;
• slideably engaging the cam pin with a final cam section of the cam slot;
• disengaging the cam pin from the final cam section;
• slideably engaging the cam pin with a re-direction surface of the cam slot having an arcuately curved concave cam profile, the re-direction surface being disposed on an opposite side of the cam slot from the final cam section;
• and
• engaging a closed front end of the cam slot with the cam pin, wherein motion of the barrel is arrested.