This SBR Ready full build kit combines a 14.5-inch 4150 CrMoV barrel with a freefloat Keymod handguard, chambered in 5.56 NATO. The kit includes an anodized 7075-T6 aluminum upper receiver with M4 feed ramps, micro low-profile gas block, carbine-length gas system, A2 birdcage flash hider, mil-spec charging handle, 5.56x45mm QPQ nitride bolt carrier group, mil-spec heavy-duty 6-position buffer tube, buffer, carbine recoil spring, castle nut, end plate, and complete mil-spec lower parts kit. Ships without a brace. Lower receiver not included.
This kit ships without a brace, intended for customers selecting their own final setup. The included mil-spec heavy-duty 6-position buffer tube, buffer, carbine recoil spring, castle nut, and end plate accommodate brace or stock attachment based on your chosen configuration.
5.56 NATO chambering provides compatibility with both 5.56 NATO and .223 Remington ammunition. The 1:7 twist rate stabilizes a wide range of bullet weights including heavier projectiles up to 77 grains.
The 5.56x45mm bolt carrier group features QPQ nitride finish over 9310 alloy steel bolt head and 8620 alloy steel body. The nitride treatment provides corrosion resistance and surface hardness while reducing friction.
This kit uses a carbine-length gas system with a stainless gas tube and .750 micro low-profile gas block positioned beneath the handguard. The carbine-length configuration is optimized for the 14.5-inch barrel length.
This full build kit is compatible with mil-spec AR-15 lower receivers. All components use standard AR-15 specifications and threading, including the 1/2x28 TPI muzzle threads matching the included A2 birdcage flash hider.
Ships without a brace. Do not install a stock unless compliant with applicable laws. Lower receiver not included. Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws.
Caliber: 5.56x45mm NATO
Barrel: 14.5" 5.56 NATO Barrel
Barrel Length: 14.5 inches
Barrel Material: 4150 CrMoV
Barrel Thread Pitch: 1/2x28
Barrel Gas System Length: Carbine
Barrel Finish: Phosphate
Barrel Profile: M4 Profile
Barrel Twist Rate: 1:7
Gas Block: Micro Low-Profile Gas Block
Gas Block Size: 0.750
Upper Receiver: AR-15 Upper Receiver
Upper Receiver Material: 7075 T6 Aluminum
Upper Receiver Finish: Anodized
Handguard Material: 6061-T6 Aluminum
Handguard Style: KeyMod
Handguard Color: Black
Muzzle Device: AR-15 1/2x28 TPI GI Birdcage Flash Hider
Muzzle Device Finish: Manganese Phosphate
Muzzle Thread Pitch: 1/2x28
Charging Handle: Standard AR-15 M4 Charging Handle
Bolt Carrier: AR-15 5.56/.223/.300/.350 Complete Bolt Carrier Group
Bolt Carrier Material: 9310 Alloy Steel for Bolt Head, 8620 Alloy Steel for Body
Bolt Carrier Finish: Nitride
To view the most up-to-date shipping times Click HERE. To view Warranty, Returns, Terms & Restrictions Click HERE. To view State Restrictions Click HERE.