UMP / USC Bolt Carrier Groups

HK Parts and Heckler and Koch HK UMP and HK USC 9mm Conversion Kit - Threaded Barrel 1/2x28 - 3-Lug This UMP, USC conversion kit will convert existing conversions to 9mm. This is a simple drop-in conversion for those who have already done the USC-UMP...

HK UMP 9mm -Semi-Auto Bolt Group The semi-auto bolt group is required for HK USC to HK UMP caliber conversions. The full-auto bolt carrier will not work in HK USC rifles. Includes: Extractor Firing pin Retaining Pin Firing pin &...

HKP HK UMP 9mm Conversion Kit -Threaded 1/2x28 9mm UMP/USC conversion kit will convert existing USC-UMP conversions to 9mm. This is a simple drop-in conversion for those that have already done the USC-UMP conversion. The conversion parts are drop in with...