JP Enterprises Stainless LMOS carrier with QPQ Black. These Bolt Carrier Groups from the experts at JP Enterprises are machined from 416 stainless steel and are finished with JP's QPQ hard coating process for better lubricity and long lasting use. The JP Enterprises Complete JPBC Bolt Carrer Group BCG bolt does not include serrations for a forward assist but does include a dust cover notch. Specifications for JP Enterprises Stainless LMOS carrier with QPQ: Manufacturer: JP Enterprises Finish: Black Caliber: .223 Remington Additional Features: with QPQ Features of JP Enterprises Complete JPBC Bolt Carrier Group BCG: Stainless LMOS carrier QPQ (without buffer) Package Contents: JP Enterprises Stainless LMOS carrier with QPQ JP Enterprises JPBC-3: Stainless LMOS carrier with QPQ Black