This is a complete upper and lower build kit designed for 5.56 NATO with a 14.5-inch carbine-length barrel, SB Tactical SBM4 pistol stabilizing brace, and freefloat M-Lok handguard. The kit ships without a stock and is configured for shooters building their own pistol setup. Lower receiver not included.
This kit ships without a brace and is intended for shooters selecting their own final setup based on their specific configuration needs. The SBM4 brace included provides a stabilizing platform for pistol shooting without converting the platform to an SBR. The configuration remains flexible depending on your intended use and local compliance requirements.
The 14.5-inch 4150 CrMoV barrel uses a 1:7 twist rate optimized for 5.56 NATO ammunition across a wide range of grain weights. The carbine-length gas system with micro low-profile gas block cycles reliably while maintaining a compact overall profile. Government profile barrel design provides durability and heat capacity for sustained fire.
The 6061-T6 aluminum M-Lok handguard floats independently from the barrel, eliminating contact that can affect accuracy. M-Lok slots provide tool-free mounting for tactical accessories, lights, and other equipment without requiring rail sections. Black anodized finish resists corrosion and blends with modern tactical setups.
The premium AR-15 5.56 complete bolt carrier group uses 9310 alloy steel with nitride finish for durability and corrosion resistance. The upper receiver features M4 feed ramps for reliable feeding and anodized aluminum construction. AR-15 M4 charging handle provides standard controls for operation.
Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Ships without a brace. Do not attach a stock unless compliant with applicable laws. Lower receiver not included.
Caliber: 5.56x45mm NATO
Barrel Length: 14.5-inch
Barrel Material: 4150 CrMoV
Barrel Thread Pitch: 1/2x28
Barrel Finish: Phosphate
Barrel Profile: Government
Barrel Twist Rate: 1:7
Gas System: Carbine
Gas Block Size: 0.750
Gas Block Name: Micro Low-Profile Gas Block
Upper Receiver Material: 7075 T6 Aluminum
Upper Receiver Finish: Anodized
Upper Receiver Name: Upper Receiver with M4 Feed Ramps
Handguard Material: 6061-T6 Aluminum
Handguard Color: Black
Handguard Style: M-Lok
Charging Handle: AR-15 M4 Charging Handle
Bolt Carrier Material: 9310 Alloy Steel
Bolt Carrier Finish: Nitride
Bolt Carrier Name: Premium AR-15 5.56 Complete Bolt Carrier Group
Brace Name: SB Tactical SBM4 Pistol Stabilizing Brace
Buffer Tube Kit Weight: 3 oz.
Muzzle Device: AR-15 1/2x28 TPI A2 Birdcage Flash Hider
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