A firearm with varying barrel camming system, the firearm comprising: a longitudinal axis; a frame; a slide movably supported on the frame for rearward and forward reciprocating movement; a barrel removably coupled to the slide and movable therewith, the barrel comprising a front muzzle end, a rear breech end defining a chamber for holding an ammunition cartridge, and axial bore extending between the ends; a camming lug protruding downward from the barrel and including a cam slot defining an upper surface and an opposing lower cam track surface, the cam slot including a rear end and an opposing front end; a cam pin fixedly mounted transversely in the frame, the cam pin arranged to slideably engage the cam track surface when the barrel is carried rearward with the slide under recoil after firing the firearm; the lower cam track surface comprising an initial cam section disposed adjacent the rear end of the cam slot, a concave intermediate varying cam section adjoining and forward of the initial cam section, and a final cam section adjoining and forward of the intermediate varying cam section, the initial and final cam sections (120, 140) each having a different cam profile than the intermediate varying cam section; wherein the cam pin slideably engages and tracks along the cam track surface after firing the firearm causing the barrel in turn to tilt and uncouple from the slide; wherein the initial and final cam sections (120, 140) each have a linear cam profile defining a flat surface oriented obliquely to the longitudinal axis of the firearm; wherein the initial cam section of the lower cam track surface is disposed at an angle between and including 15 to 20 degrees to a horizontal reference plane, and the final cam section is disposed at an angle of more than 30 degrees and less than 60 degrees to the horizontal reference plane. a longitudinal axis; a frame; a slide movably supported on the frame for rearward and forward reciprocating movement; a barrel removably coupled to the slide and movable therewith, the barrel comprising a front muzzle end, a rear breech end defining a chamber for holding an ammunition cartridge, and axial bore extending between the ends; a camming lug protruding downward from the barrel and including a cam slot defining an upper surface and an opposing lower cam track surface, the cam slot including a rear end and an opposing front end; a cam pin fixedly mounted transversely in the frame, the cam pin arranged to slideably engage the cam track surface when the barrel is carried rearward with the slide under recoil after firing the firearm; the lower cam track surface comprising an initial cam section disposed adjacent the rear end of the cam slot, a concave intermediate varying cam section adjoining and forward of the initial cam section, and a final cam section adjoining and forward of the intermediate varying cam section, the initial and final cam sections (120, 140) each having a different cam profile than the intermediate varying cam section; wherein the cam pin slideably engages and tracks along the cam track surface after firing the firearm causing the barrel in turn to tilt and uncouple from the slide; wherein the initial and final cam sections (120, 140) each have a linear cam profile defining a flat surface oriented obliquely to the longitudinal axis of the firearm; wherein the initial cam section of the lower cam track surface is disposed at an angle between and including 15 to 20 degrees to a horizontal reference plane, and the final cam section is disposed at an angle of more than 30 degrees and less than 60 degrees to the horizontal reference plane.