Most handguns will require a specific chassis and 16” barrel engineered for that model, make, etc.
Some exceptions are Glock 17, 19, 22 and 23 handguns. All of those models require a different barrel, but they will all fit inside the Apex GFC Chassis. If you bought an APEX kit for your Glock 19 or 23 (compact size), you will have to remove the set-screw in the “C” position of the top-rail if you want to fit your Glock 17 or 22 (full-size).
