AR-15 Rifle Features The Great Lakes Firearms and Ammunition AR-15 rifle features M4 feed ramps a 15.25 inch M-LOK aluminum handguard a 6-position collapsible synthetic stock and a 30 round magazine. AR-15 Rifle Specifications Action: Semi-Automatic Ambidextrous Safety: No Barrel: 16 inch 1:8 Twist Heavy Barrel (HBAR) - Either 416R SS or 4150 CRMOV Nitride 1/2 x 28 threads Caliber: .223 Wylde (Shoots both .223 REM and 5.56 NATO) Feed Ramps: M4 Finish: Cerakote Frame Material: Aluminum 7075 Gas System: 0.750 Gas Block (Black Oxide) and Carbine Gas Tube Grip: Mil-spec Polymer Handguard: 15.25 M-Lok Aluminum 6061 - Full picatinny rail Magazine Capacity: 30 Round Mags included: 1 Muzzle Brake: Included - Designed to be 6 degrees forward wrench tightened w/o Loctite Sights: None Trigger: Milspec 5.5-6 lb pull Upper: 7075 Upper Overall Length: 33.25" Weight: 6.8 lbs.