CU5-556-P1 – 5″ 5.56 NATO Complete Upper with Phase 1 Brake

Description

5.56 NATO Complete Upper Receiver (CU5-556-P1)

Our Complete Barreled Uppers are fully assembled in-house and ready to pin to your lower receiver. We use forged American-made receivers and US-made barrels—carefully selected for quality, reliability, and consistency. Every upper is assembled right here in Arlington, Texas.

Optional: Black Nitride M4-cut BCG.

Specs

• Caliber: 5.56×45 NATO/.223 Remington
• Barrel Length: 5“
• Barrel Material: 4150V Chrome Moly Vanadium, QPQ finish
• Barrel Twist Rate: 1:5
• Feed Ramps: M4, NiB finish
• Muzzle Thread Pitch: 1/2×28
• Gas System: Micro-length
• Journal Size: 0.750″
• Muzzle Device: Phase 1 Muzzle Device
• Handguard Length: 4“
• Charging handle: Mil-spec

Check out our blog for more info on parts compatibility, build help, assembly guides, and more!

The XTS ADZ Rail uses 6061-T6 aluminum and comes anodized in six colors. It features a full-length Picatinny top rail, M-LOK slots at 3, 6, and 9 o’clock, and QD sling sockets at both ends. A two-bolt clamping base locks it firmly to the barrel nut.