The Ruger AR-556 Pistol features a lower receiver that is fitted with an adjustable pistol stabilizing brace to aid in accuracy, balance and recoil management, the slim 9" handguard is free-floating for accuracy and provides enhanced ergonomics and support. Magpul M-LOK accessory attachment slots along the 3:00, 6:00 and 9:00 positions. Made from aerospace-grade 7075-T6 aluminum forging, the flattop upper receiver includes a forward assist, dust cover and brass deflector. The bolt is machined from 9310 alloy steel and is shot peened and pressure (proof) tested to ensure strength, structural integrity, and durability.