Big Bore Upper Receiver – Skeletonized


In Stock

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.


AR-15 upper receiver with ejection port opened up to allow the large caliber cartridges to eject.  Works with 375 SOCOM, .458 SOCOM, 450 Bushmaster, 12.7×42, as well as other large diameter cartridges.  Includes forward assist assembly and ejection port cover assembly.

These have no caliber designation engraved on the side.