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 German USC .45 Factory Semi Bolt - Incomplete HK German USC, Omega GS 45 caliber bolt carrier that is stripped. Just add the firing pin, firing pin spring, extractor and firing pin retaining pin for a complete bolt. Made in Germany.

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...

German UMP .40 factory F/A Bolt Group - Complete This item is used in very good shape.

New US-Made USC & UMP 9mm Extractor: This is the perfect spare part for your UMP or USC 9mm conversion.  Please Note: HK considers this a high wear and replacement item. Once it's removed from the carrier, the spring tension...

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...

Omega HK UMP .45 Bolt Carrier Complete - Semi Auto Replacement part for USC to UMP conversions. Marked .45 semi auto just like the OEM carrier. Compatible With: HK UMP .45 Includes: Extractor Firing Pin Firing Pin Spring Firing Pin Retaining Pin The...

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...