Sir/Ma'am,I received this kit and installed the barrel and bolt. I then found a black, tapered ring in the bottom of the box. What is it for? I do not see it anywhere in the manual.v/rScott
Referenced item: CALX-MCX-9B-300-TAP
That tapered ring sounds like the adapter for a non-tapered (non-Sig) suppressor or muzzle device.