Action: Semi-Automatic - Caliber: .223 Remington 5.56 x 45 mm NATO - Barrel Length: 14.5 - Twist Rate: 1:7 - Barrel Contour: Government - Barrel Material: 4150 Chrome Moly Vanadium Steel - Muzzle Thread Pattern: 1/2-28 - Muzzle Device: Pinned VDI Manimal Flash Hider - Chrome Lined: No - Barrel Finish: QPQ Melonite / Black Nitride - Upper Receiver: A4 Flat-Top Forged - Trigger: Mil-Spec Standard Trigger - Bolt Carrier: 1-Piece w/Integral Piston Strike Face - M4 Feed Ramps: Yes - Gas System Length: Mid Short Stroke Piston Operated - Gas Block Diameter: 0.750 - Sights: None Single Rail Gas Block - Stock: Enhanced 6-Position Buttstock - Grip: Ergo Grip - Handguard: Evolution Rail - XLP Multi-Adjustable Low Profile Gas Block - Weight: 6.889 lbs - Trigger: Standard - Purpose: Personal Protection/Sport - Mil-Spec Forged 7075-T6 Lower Receiver Type III Class II Hard-coat anodized finish beveled magwell machined chevrons in front strap - Mil-Spec Forged 7075-T6 M-4 Upper Receiver Type III Class II Hard-coat anodized finish M4 feed ramps 1913 Picatinny rail flat top with dry lube internal finish and laser engraved T-markings - 14.5 Government Contour 4150 CM Melonited Barrel 1:7 twist - Pinned Manimal Flash Hider - 30 round GI Aluminum Magazine - Samson free float light weight modular rail system - The 5.56 Mid Length Tactical Evo 14.5 Rifle is a standard mil-spec rifle that incorporates the patented Adams Arms technology and the Samson Evolution extended free floating forearm. The midlength piston system will give you the benefits of a longer forearm by giving the user a longer more ergonomic grip a longer sight radius between the front and rear sight for quicker sight acquisition and less felt recoil.