Big Bore Upper Receiver – Left Handed


Blend Feed Ramp

We will blend the feed ramp for you for an additional fee, but you must purchase the barrel and receiver together at the same time in order for us to do this.


Left hand AR-15 upper receiver with enlarged ejection port for use with 458 SOCOM, 375 SOCOM, and 450 Bushmaster. Requires the use of a left hand bolt and left hand carrier.  Includes ejection port cover and forward assist assembly.
Unlike our right handed uppers, these are not engraved with any logo or caliber designation.
All Tromix barrels will work in both left and right hand configurations.