AR Parts in 5.56x45mm NATO

Green Mountain 5.56 AR-15 Barrel 14.5" M4 Phosphate

Green Mountain 5.56 AR-15 Barrel 14.5" M4 Phosphate

Green Mountain 5.56 AR-15 Barrel 14.5" M4 Phosphate

Green Mountain 5.56 AR-15 Barrel 14.5" M4 A1 Phosphate

Green Mountain 5.56 AR-15 Barrel 12.7" M4 A1 Phosphate

Green Mountain 5.56 AR-15 Barrel 11.5" M4 Finned Phosphate

Green Mountain 5.56 AR-15 Barrel 11.5" M4 A1 Phosphate

Green Mountain 5.56 AR-15 Barrel 10.5" M4 Phosphate

Green Mountain 5.56 AR-15 Barrel 10.3" M4 Phosphate

16" 5.56 NATO 1:8 Twist Black Nitride M4 Mid-Length Barrel

Cloak Industries MFR 56 Belt-Fed Dual-Feed 16" Quick-Change AR-15 Upper - Black

Ballistic Advantage 16" 5.56 1:7 Carbine Length Chrome/Phosphate Barrel

Ballistic Advantage 11.5" 5.56 Hanson Carbine Cold Hammer Forged Barrel w/ .750 Low Pro Gas Block 1:7 Twist

Aero Precision AR-15 M4E1 Enhanced Upper Receiver - Kodiak Brown

One Horse 16" 5.56 SOCOM Midlength 1:7 M-LOK Upper Assembly

One Horse 16" 5.56 SOCOM Midlength 1:8 M-LOK Complete Upper

One Horse M16 .223/5.56 Bolt Carrier Group - Black Nitride

BCA M16 Cut 5.56/.223 Right Side Charging Complete BCG - Black Nitride

NBS 7.5" Slick Side Billet 5.56 Nitride Pistol M-LOK Upper Assembly

Obsidian Arms Enhanced AR-15 Bolt Carrier Pin Kit

Obsidian Arms M16 Bolt Carrier Group Phosphate 5.56

Aero Precision M4E1-E 16" Mid 5.56 Complete Upper, No Forward Assist, EM15 Handguard - Black

Aero M4E1-E Complete 16" Upper, 5.56 Mid Hanson Barrel, 15" Enhanced Handguard - Black

Evolve Weapons Systems Bolt Carrier Group - Phosphate