This flat top upper assembly from Bushmaster is chambered in .300 AAC Blackout and features a 16" 4150 chrome moly steel barrel with salt bath nitride finish. The barrel is free floated within the quad rail handguard. The muzzle is threaded 5/8x24 and fitted with an AAC Blackout flash hider. The upper assembly is complete with bolt carrier group, forward assist, ejection port cover and charging handle. Just pin on any complete AR-15 and add your favorite sights or optics.

Specifications and Features:
Bushmaster 92866
.300 AAC Blackout
Pistol length gas system
16" chrome moly barrel with nitride finish
1:7" twist
M4 feed ramps
Muzzle threaded 5/8x24
AAC Blackout flash hider
Free float quad rail
Bolt carrier group
Charging handle
Forward assist
Black