Sons of Liberty Gun Works SCALPER, AR-15 Receiver Set, Cerakote Finish, Flat Dark Earth, Includes Upper and Lower Stripped Receiver SCALPERSET-FDE The Sons of Liberty Gun Works stripped upper and lower receivers are made to the tightest tolerances while still being compatible with Mil-Spec parts and upper receivers. This ensures that there is absolutely no wobble between receivers which can affect accuracy. They are forged from 7075-T6 aluminum, which is known for its high strength and crack resistant properties while also being lighter than 6061. After the forging process is complete, the receivers go through a final machining process to eliminate flash marks and true up the tolerances to be better than MIL-SPEC. Get your build started today with the SOLGW stripped upper receiver.