UMP / USC Bolt Carrier Groups

MM HK UMP, USC Conversion Kit - 9mm This 9mm conversion kit is designed for USC-to-UMP builds and allows existing .45 ACP conversions to be changed over to 9mm with a simple, drop-in parts swap. All components install in minutes and are built to...

HK UMP .40 Caliber Conversion Kit This UMP conversion kit provides the necessary components to convert .45 sub-guns to .40 caliber. Machined bolt carriers are available for USC/UMP conversion sub-guns. This is a simple, drop-in conversion requiring a...