AR-10® B-Series 18" 3-Gun Complete Upper Half Assembly

AR-10® B-Series 18″ Competition Complete Upper Half Assembly


The AR103GN’s are Armalite’s flagship competition rifles that are built to win.  This upper is light and ultra-fast.  The low profile handguard covers a free-floating 18-in. barrel with Armalite’s own tunable muzzle brake.  An adjustable gas block also allows the rifle to be individually set for optimal performance.

All Armalite complete upper half assemblies include a bolt carrier group and charging handle.

Out of stock

7.62X51mm / .308
18" stainless steel
Rifle length gas system
Rifling Twist
1:10" RH
Muzzle Device
Armalite tunable brake
Front Sight Base
2" MIL-STD 1913 rail section at forward 12 O'clock position of handguard
15" free-floating 3-Gun
Upper Receiver
Forged, flat-top with MIL-STD 1913 rail, 7075-T6 aluminum
Charging Handle
"Raptor" ambidextrous
Anodized aluminum upper receiver
Overall Length
5.1 lbs.