Product Description
MCS AR-15 5″ 5.56 NATO PISTOL UPPER BUILT WITH PHASE 1 MUZZLE SYSTEM
Our premium built AR 5" uppers are fully assembled in-house and ready to pin to your lower receiver. We use forged American-made receivers and USA made barrels—carefully selected for quality, reliability, and consistency backed by our full warranty.
- 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
Phase 1 Muzzle Device
The Modular Muzzle System is not just a muzzle brake — it’s a precision-engineered host platform built around a dual/nested taper alignment interface for unmatched concentricity and repeatability.
Designed from the ground up for modern rifle builds, this hybrid system pairs a high-efficiency staged brake with a thread-over flash splitter/cone module. The result? Controlled recoil, reduced muzzle rise, forward blast management, and suppressor-host-ready alignment — all in one modular ecosystem.
Purpose-built for 13.7” and 13.9” barrels, the system adds + 2.325” in length, bringing compliant 16” OAL when permanently attached.
This is modularity done right — engineered from inception, not added as an afterthought.
- Dual-Taper Precision Lockup
- Integrated Pin/Weld Hole (Converts 13.7″ to Rifle Length)
- Duty-Rated Construction
- Sequential Port Geometry
- Use for Recoil or Flash Mitigation
