AR Parts in 5.56x45mm NATO

Sionics Weapon Systems (SWS) AR-15 Bolt Carrier Group - Phosphate

Sharps Rifle Company Xtreme Performance Bolt Nickel Boron

Rubber City Armory AR-15 5.56/.223 Bolt Carrier Group (BCG) - Black Nitride

Rosco Manufacturing Bloodline 16" 5.56 Government 1:7 Twist Black Nitride Midlength Barrel w/ FSB

Rosco Manufacturing Bloodline 14.5" 5.56 M4 1:7 Twist Black Nitride Carbine Barrel w/ FSB

Rock River Arms A1 Retro AR-15 Complete Upper Receiver 5.56x45mm NATO 20" Barrel

Retro-Arms MOD 10 Long AR-15 Complete Upper Receiver Assembly 5.56x45mm NATO 16" Barrel

Retro-Arms Light Support Weapon AR-15 Upper Receiver Assembly 20" Barrel 5.56x45mm NATO

Retro-Arms C8A1 CQB AR-15 Complete Upper Receiver 5.56x45mm NATO 10.5" Barrel

Retro-Arms M16A4 AR-15 Barreled Upper Receiver 5.56x45mm NATO 20" Barrel

Rainier Arms AR-15 M-LOK SWITCH .223/5.56 Rail

Rainier Arms / Rellim Arms AR-15 5.56 NATO Take Down Upper Receiver Assembly - 16"

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 14.5" FDE

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 12.5"

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 10.5"

Rainier Arms RUC DI 5.56 NATO Partial Upper Receiver

Rainier Arms Select 5.56 NATO M16A1 AR-15 Barrel - 20"

Rainier Arms Select 5.56 NATO AR-15 Barrel - 18"

Rainier Arms Select 5.56 NATO Dissipator AR-15 Barrel - 16"

Rainier Arms Select 5.56 NATO AR-15 Barrel - 16"

Rainier Arms Select 5.56 NATO AR-15 Barrel - 14.5"

Rainier Arms Select 5.56 NATO AR-15 Barrel - 12.5"

Rainier Arms Select 5.56 NATO AR-15 Barrel - 11.5"