Caliber Conversion Kits

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...

Used Surplus Genuine German HK G3 .22 caliber conversion kit Fits and converts all HK91, G3 rifles to shoot the cheap and readily affordable .22 LR ammunition. Includes bolt group, barrel tube, 1 magazine, and cleaning kit and wooden green case. NO...

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 UMP & USC 9mm Conversion Kit US Made - 9mm 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...

HK G36C .300 Blackout Caliber Parts Kit- USA Complete G36C Semi-Auto Parts Kit. This kit includes all parts needed for a complete build minus the receiver. The barrel and gas block are Black Nitride coated for longevity and resistance against wear and...

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...

HK UMP 9mm Conversersion Kit - USA - 9mm 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 total conversion requires approximately...

HK UMP 9mm Conversion Kit - Threaded Barrel 1/2 x 28 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...

HK G36C 556/223 To .300 Blackout Caliber Conversion - USA The Tom Bostic .300 BLK conversion barrel set up is designed to drop in any G36C or Sl8 to G36C conversion and reuse your G36C op-rod/spring set, gas piston & barrel nut. Each set up comes...