Rock River Arms A4

Rock River Arms Completed Pistol Upper Receiver A4 .223/5.56mm 7 Inch Barrel 1-9 Twist 1/2-28 Thread Free-Float Handguard A2 Flash Hide Black

Rock River Arms Completed Upper Receiver Mid-Length A4 9MM Luger 16 Inch Barrel 1-10 Twist 1/2-36 Thread A2 Flash Hider Black

Rock River Arms Completed Upper Receiver Varmint A4 .308/7.62X51mm NATO 20 Inch Barrel 1-10 Twist Free-Float Handguard Black

Rock River Arms Completed Upper Receiver Predator HP A4 .308/7.62X51mm NATO 16 Inch Barrel 1-10 Twist Free-Float Handguard Brake Black

Rock River Arms Completed Upper Receiver Entry Tactical A4 .223/5.56mm 16 Inch Barrel 1-9 Twist 1/2-28 Thread R4 Handguard A2 Flash Hider Black

Rock River Arms Completed Upper Receiver Operator ETR .308/7.62x51mm 16 Inch Barrel 1-10 Twist Mid-Length Profile 5/8-24 Threat Free-Float Handguard

Rock River Arms Completed BilletvUpper Receiver .308/7.62X51mm 18 Inch Barrel 1-10 Twist Mid-Length Profile 5/8-24 Threat Free-Float Handguard Brake