.223 Rem | 5.56 NATO

Springfield Armory

Springfield Armory Hellion SPG HL916556B 5.56x45mm NATO Bullpup Rifle with 16-Inch Barrel and Adjustable Stock

Springfield Armory

Springfield Armory SPG HL920556BCA Hellion 5.56 NATO Bullpup Rifle, 20-Inch Barrel, Black Finish

Sig Sauer

Sig Sauer M400 SDI 5.56 NATO Rifle with 16-Inch Threaded Barrel and Magpul SL Stock RM400SDI16BR5FX

Springfield Armory

Springfield Armory HL916556Y Hellion 5.56 NATO 16-inch Bullpup Rifle in Gray

Springfield Armory

Springfield Armory HL916556YLC Hellion 5.56 NATO 16-Inch Bullpup Rifle in Gray

Springfield Armory

Springfield Armory Hellion SPG HL916556F 5.56mm NATO Bullpup Rifle with 16-Inch Barrel in Flat Dark Earth

Springfield Armory

Springfield Armory HL916556G Hellion 5.56mm Bullpup Rifle with 16-Inch Barrel and Ambidextrous Features

Springfield Armory

Springfield Armory SPG HL918556B Hellion 5.56 NATO 18-inch Bullpup Rifle with Adjustable Stock and Flip-Up Sights

Springfield Armory

Springfield Armory HL920556B Hellion 5.56 NATO 20-Inch Bullpup Rifle with Ambidextrous Safety and Flip-Up Sights

Springfield Armory

Springfield Armory HL916556FLC Hellion 5.56 NATO 16-Inch Bullpup Rifle with Adjustable Stock and Ambidextrous Safety

Springfield Armory

Springfield Armory HL916556GLC Hellion 5.56 NATO 16-inch Bullpup Rifle with Adjustable Stock and Ambidextrous Safety

Sig Sauer

Sig Sauer R516G3556N16B 516 G3 Mohawk 5.56 NATO Semi-Auto Rifle with 16-Inch Barrel and Black Finish