Colt AR-15 Pistol Upper Receiver Assembly - 5.56x45mm, 14.5" Barrel, No Handguard

Building a custom AR pistol or short-barrel rifle? The Colt AR-15 pistol upper receiver assembly in 5.56x45mm NATO gives you a proven platform without the unnecessary factory handguard. This 14.5" barreled upper comes stripped of rail furniture, letting you bolt on the free-float handguard of your choice—whether that's a lightweight tube, a modern M-LOK system, or anything in between. It's a straightforward approach: pay only for what you'll actually use, then customize to your needs.

The upper features a 1:7 twist button-rifled barrel with a standard 1/2"-28 threaded muzzle, paired with a low-profile gas block engineered to work under most contemporary handguards without fitment drama. That gas block clearance matters when you're running premium aftermarket rail systems. Everything you need to complete a functioning upper is in the box: the bolt-carrier group, charging handle, and barrel extension—no surprises, no missing parts.

Whether you're building a precision rifle, a compact combat platform, or a home-defense AR pistol, this Colt upper gives you a quality foundation with real-world compatibility. Colt's manufacturing heritage means the barrel extension and receiver fitment are tight and reliable. From there, the build is yours to customize.

Key Features

• 5.56x45mm NATO chambering, 14.5" button-rifled barrel
• 1:7 twist rate suitable for the full spectrum of 5.56 ammunition weights
• Threaded 1/2"-28 TPI muzzle for suppressors and muzzle devices
• Low-profile gas block clears free-float handguards
• No factory handguard—choose your own rail system
• Bolt-carrier group and charging handle included
• Proven Colt manufacturing and quality control

Specifications

Frequently Asked Questions

What handguards will fit this Colt upper?

The low-profile gas block is designed to clear most modern free-float handguards on the market. Any handguard with a standard AR-15 receiver extension will fit. Confirm your specific rail choice clears the gas block before purchase.

Is a bolt-carrier group included?

Yes. This upper assembly ships complete with the bolt-carrier group and charging handle, so you're ready to pair it with a lower receiver and start building.

Can I use this for a short-barrel rifle or AR pistol?

The upper itself is caliber and mechanical neutral—it will work with any AR-15 compatible lower receiver. Your configuration (rifle vs. pistol) is determined by the lower and your final assembly. Always verify your build complies with local and federal firearms laws.

What muzzle devices can I attach?

The 1/2"-28 threaded muzzle accepts any muzzle device compatible with that standard: suppressors, brakes, flash hiders, compensators, and more. Verify your device of choice is legal in your jurisdiction before installing.