XCR Parts XCR-L Lower Receiver Parts Shop Now XCR-L Bolt & Carrier Parts Shop Now XCR-L Upper Receiver Parts Shop Now XCR-L Oprod & Recoil Spring Parts Shop Now XCR-M Lower Receiver Parts Shop Now XCR-M Bolt & Carrier Parts Shop Now XCR-M Upper Receiver Parts Shop Now XCR FAST2 Stock Parts Shop Now