6.8 x 51mm

Sig Sauer

Sig Sauer SigHYP 6.8x51mm AR-15 Rifle with 16-Inch Barrel, 20-Round Capacity, Black

Sig Sauer

Sig Sauer MCX Spear 6.8x51mm Rifle with 16-Inch Barrel and Folding Stock - Model RSPEAR6816BNG