The Springfield Armory® Hellion represents a radically unique and innovative approach to firearms design helping to redefine perceptions of semi-automatic 5.56mm performance. Featuring a bullpup configuration where the action is located behind the trigger the Hellion 18 features a short overall length for compact handling along with enhanced ballistic performance due to its longer barrel. Ambidextrous controls work in concert with a reversible case ejection system for maximum adaptability. The result is a 5.56 that combines portability with potent performance. – Caliber 5.56x45mm NATO (.223 REM) – Color Black – Barrel 18 CMV Melonite® 1:7 – Front Sight Integrated Flip-Up Elevation Adjustable – Rear Sight Integrated Flip-Up w/ 5-Position Aperture Windage Adjustable – Bolt Carrier Group Proprietary Melonite® – Gas System 2-Position Adjustable Short Stroke Piston – Handguard Polymer M-Lok® – Stock 5-Position Adjustable w/ Cheek Riser – Muzzle Device 4-Prong Flash Hider – Charging Handle Ambidextrous Non-Reciprocating – Safety Switch Ambidextrous – Grip BCMGUNFIGHTER Mod 3 – Magazines (1) 30-Round Magpul PMAG Gen M3 – Weight 8 lbs 3 oz – Length 30.25-31.75