.223 Rem | 5.56 NATO

Springfield Armory

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

Sig Sauer

Sig Sauer RM400SDI16BP M400 X-Series 5.56x45mm Rifle with 16-Inch Barrel and Magpul SL-K Stock

Sig Sauer

Sig Sauer M400 SDI 5.56 NATO Semi-Auto Rifle with 11.5-Inch Barrel, Black Finish

Sig Sauer

Sig Sauer RMCX556N16BLTB MCX 5.56 NATO 16-Inch Barrel Rifle with Black Finish

Springfield Armory

Springfield Armory SPG SA920556BA2 5.56x45mm NATO Semi-Auto Rifle with 20-inch Barrel and A2 Fixed Stock

Sig Sauer

Sig Sauer M400 5.56 NATO Semi-Auto Rifle with 16-Inch Threaded Barrel and Magpul SL-K Stock

Sig Sauer

Sig Sauer RM40016BROSER5X2 5.56 NATO Semi-Auto Rifle with 16-inch Threaded Barrel and Magpul MOE SL Stock

Springfield Armory

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

Sig Sauer

Sig Sauer MCX Spear LT 5.56 NATO Rifle with Folding Brace and 11.5-inch Barrel - Part Number PMCX556N11BIR10

Sig Sauer

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

Sig Sauer

Sig Sauer RMCX556N16BIR MCX Spear LT 5.56 NATO Rifle with 16-Inch Barrel and Folding Stock

Sig Sauer

Sig Sauer MCX Spear LT 5.56 NATO Rifle with Folding Brace and 30-Round Capacity - Model PMCX556N11BIR