Davidson Defense Mutton Chops w/SBA3 Brace 10.5-inch Pistol-Gas 1:8 .338 ARC AR-15 Freefloat Keymod Handguard Pistol Full Build Kit

Mutton Chops SBA3 Brace 10.5-inch Pistol-Gas 1:8 .338 ARC AR-15 Freefloat Keymod Pistol Full Build Kit

The Mutton Chops is a .338 ARC AR-15 Full Build Kit built around a compact 10.5-inch pistol-length gas platform. The kit centers on a 10.5-inch Bear Creek Arsenal HBAR profile 4150 CrMoV steel barrel with a parkerized finish, 1:8 twist rate, and 5/8x24 thread pitch, paired with a GI birdcage flash hider compatible with .308 Winchester, 7.62x39, .300 AAC Blackout, and .338 ARC, 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 complete 6.5 Grendel Type II QPQ nitride bolt carrier group compatible with the .338 ARC platform 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 Bear Creek Arsenal HBAR profile 4150 CrMoV steel barrel, parkerized finish, 1:8 twist, 5/8x24 thread pitch, .338 ARC
• 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 and .338 ARC 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
• Complete 6.5 Grendel Type II QPQ nitride bolt carrier group, .338 ARC 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 .338 ARC AR-15 pistol full build kit with a Bear Creek Arsenal 4150 CrMoV barrel, 6.5 Grendel Type II QPQ nitride 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 .338 ARC platform who want the Grendel Type II 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 .338 ARC full build kit with a Bear Creek Arsenal 4150 CrMoV barrel, ultra-slim freefloat Keymod handguard, and complete lower parts kit without sourcing components separately

Barrel and Muzzle Device

The 10.5-inch Bear Creek Arsenal HBAR profile barrel is chambered in .338 ARC and constructed from 4150 CrMoV steel with a parkerized finish. The twist rate is 1:8 and the thread pitch is 5/8x24, which matches the included GI birdcage flash hider. The flash hider is compatible with .308 Winchester, 7.62x39, .300 AAC Blackout, and .338 ARC. 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 complete 6.5 Grendel Type II QPQ nitride bolt carrier group is compatible with the .338 ARC platform due to the shared 6.5 Grendel bolt pattern. 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.