UMP / USC Bolt Carrier Groups

HK UMP 9mm Conversion Kit - US-Made UMP/USC conversion kit will convert existing USC-UMP conversions to 9mm. This is a simple drop-in conversion for those who have already done the USC-UMP conversion. The conversion parts are drop-in, with the total swap...

HK UMP 40 Caliber Conversion Kit With this UMP Conversion kit, UMP .45 sub guns can be converted to .40 caliber. Machined bolt carriers are available for USC/UMP conversion sub guns. This is a simple drop-in conversion. The time required to change...

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...