Includes:

• Adjustable Gas Piston System installed

• Bolt Carrier for use with Piston (not compatible with DI gas key)

Choose the BCG parts kits for a complete BCG, all parts are coated in Nickel Boron - any special requests, please fill out the contact form first

Lapping the upper receiver removes the finish and any imperfections in the metal where the barrel mates with the receiver. This ensures a square fit and alignment of the barrel from the receiver.