Davidson Defense Mutton Chops w/SBA3 Brace 10.5-inch Pistol-Gas 1:8 .300 BLK AR-15 Freefloat Keymod Handguard Pistol Full Build Kit

Mutton Chops SBA3 Brace 10.5-inch Pistol-Gas 1:8 .300 BLK AR-15 Freefloat Keymod Pistol Full Build Kit

The Mutton Chops is a .300 AAC Blackout AR-15 Full Build Kit built around a compact 10.5-inch pistol-length gas platform. The kit centers on a 10.5-inch HBAR profile parkerized barrel with a 1:8 twist rate and 5/8x24 thread pitch, paired with a GI birdcage flash hider compatible with .308 Winchester, 7.62x39, and .300 AAC Blackout, and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a pistol-length stainless steel gas tube are included on the front end. The 7075-T6 aluminum anodized upper receiver features M4 feed ramps, an ejection port door with rod and spring, and a forward assist assembly, paired with a 10-inch ultra-slim freefloat Keymod handguard in aluminum. A USA-made complete AR-15 bolt carrier group compatible with 5.56 NATO, .223 Remington, .300 AAC Blackout, and .350 Legend, and a Mil-Spec AR-15 M4 charging handle complete the upper side. The lower hardware includes a complete Mil-Spec AR-15 lower parts kit, a Mil-Spec heavy-duty 6-position receiver extension, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, a Mil-Spec AR-15 M16 style receiver end plate, and a standard AR-15 carbine castle nut. The SB Tactical SBA3 5-position adjustable pistol stabilizing brace in black is included. Lower receiver not included.

Key Features

• 10.5-inch HBAR profile parkerized barrel, 1:8 twist, 5/8x24 thread pitch, .300 AAC Blackout
• Pistol-length gas system
• Pistol-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• GI birdcage flash hider, 5/8x24, .308 Winchester and 7.62x39 and .300 AAC Blackout compatible, black crush washer included
• 7075-T6 aluminum upper receiver, anodized, M4 feed ramps, ejection port door with rod and spring, forward assist assembly
• 10-inch ultra-slim freefloat Keymod handguard, aluminum
• USA-made complete AR-15 bolt carrier group, 5.56 NATO and .223 Remington and .300 AAC Blackout and .350 Legend compatible
• Mil-Spec AR-15 M4 charging handle
• Complete Mil-Spec AR-15 lower parts kit
• Mil-Spec heavy-duty 6-position receiver extension
• Standard carbine buffer, 3 oz
• Standard AR-15 carbine recoil spring, made in USA
• Mil-Spec AR-15 M16 style receiver end plate
• Standard AR-15 carbine castle nut
• SB Tactical SBA3 5-position adjustable pistol stabilizing brace, black

Perfect For

• Builders sourcing a complete .300 AAC Blackout AR-15 pistol full build kit with a 7075-T6 anodized upper receiver, USA-made BCG, ultra-slim freefloat Keymod handguard, and SBA3 5-position adjustable brace already included, pairing it with their own lower receiver
• Shooters building a compact 10.5-inch pistol-gas .300 BLK platform who want the USA-made BCG, charging handle, Mil-Spec buffer tube, and SBA3 adjustable brace covered in one kit with a GI birdcage flash hider at 5/8x24
• AR-15 pistol builders who want a .300 AAC Blackout full build kit with an ultra-slim freefloat Keymod handguard, USA-made BCG, and complete lower parts kit without sourcing components separately

Barrel and Muzzle Device

The 10.5-inch HBAR profile barrel is chambered in .300 AAC Blackout and finished in parkerized with a 1:8 twist rate and 5/8x24 thread pitch, which matches the included GI birdcage flash hider. The flash hider is compatible with .308 Winchester, 7.62x39, and .300 AAC Blackout. A black crush washer, a micro low-profile steel gas block at 0.750 diameter, and a pistol-length stainless steel gas tube cover the front end gas configuration on this pistol-length platform.

Upper Receiver and Handguard

The 7075-T6 aluminum upper receiver carries an anodized finish with M4 feed ramps, an ejection port door with rod and spring, and a forward assist assembly. The 10-inch ultra-slim freefloat Keymod handguard is aluminum with Keymod attachment points along the body for accessory mounting. These two components define the exterior structure of the upper assembly on this AR-15 pistol platform.

Bolt Carrier Group and Charging Handle

The USA-made complete AR-15 bolt carrier group is compatible with 5.56 NATO, .223 Remington, .300 AAC Blackout, and .350 Legend. A Mil-Spec AR-15 M4 charging handle is included to complete the upper component set.

Lower Parts Kit and Buffer System

The complete Mil-Spec AR-15 lower parts kit covers the internal lower receiver components. The buffer system includes a Mil-Spec heavy-duty 6-position receiver extension, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, a Mil-Spec AR-15 M16 style receiver end plate, and a standard AR-15 carbine castle nut. The SB Tactical SBA3 5-position adjustable pistol stabilizing brace in black pairs with the included Mil-Spec buffer tube and covers the rear brace interface for this pistol lower build kit.

Follow safe handling and manufacturer instructions. Ensure compliance with all applicable federal, state, and local laws. Lower receiver not included. Verify local and state laws regarding pistol brace use and classification.