CMC Triggers AR-15 Stripped Upper Receiver Features The CMC Triggers AR-15 Stripped Upper Receiver starts every build with forged 7075-T6 aluminum a material chosen because the forging process compresses and aligns the grain structure more densely than a machined billet blank. That tighter grain structure is what gives a forged receiver its reputation for standing up to hard use without stress cracking at thin wall sections over time. Machining is held to M16/M4 military specifications which means a barrel handguard and bolt carrier group built to the same mil-spec dimensions will drop in without the fitting or shimming that off-spec receivers sometimes demand. This matters most to builders assembling a rifle from parts across multiple manufacturers since mil-spec tolerances are the common language that lets those components work together. M4 feed ramps are cut into the receiver where it meets the barrel extension smoothing the path a round travels out of the magazine and into the chamber during the feeding cycle. That ramp geometry reduces the odds of a round nose-diving or hanging up during rapid-fire strings a detail that matters whether the finished rifle is built for duty competition or range use. The top of the receiver carries a full-length MIL-STD-1913 Picatinny rail giving the builder a standardized mounting surface for a red dot magnified optic or iron sights without needing an aftermarket rail section. Shipping stripped with no internals installed this AR-15 upper receiver is for sale at GrabAGun as a clean mil-spec starting point for a custom build. CMC Triggers AR-15 Stripped Upper Receiver Specifications Manufacturer: CMC Triggers Model: AR-15 Stripped Upper Receiver Type: Upper Receiver Caliber: 5.56 NATO Color: Black Material: 7075-T6 Forged Aluminum Machining Standard: M16/M4 Mil-Spec Feed Ramps: M4 Feed Ramps Top Rail: MIL-STD-1913 Picatinny Compatible Hosts: AR-15 Condition: Stripped No Internals Available At: GrabAGun