Due to the rise in popularity of Pistol Caliber Carbine (PCC) rifles and after careful research and development, CMC Trigger launched the CMC 9mm PCC Drop-in Trigger. The trigger's hammer dimensions have been modified to work with all the various manufacturer bolt carriers designed for the 9mm platform. The CMC PCC trigger features a non-adjustable 3.5lb pull that breaks like glass.CMC Triggers is the original manufacturer of the Drop-in Trigger Group for the AR-15/10 rifle since 2003. CMC's critical sear engagement surfaces have a proprietary machining process that renders superior surface finish and dimensional control. As compared to their competition, the techniques used to establish a 1-2 RMS surface finish as opposed to EDMing which leaves a pitty 32 RMS, compared to a mirror which is 0 RMS.