Davidson Defense Hammer Forge w/Magpul BTR Brace 10.5-inch Carbine-Gas 1:24 .450 Bushmaster AR-15 Freefloat Keymod Handguard Pistol Full Build Kit

Hammer Forge Magpul BTR Brace 10.5-inch Carbine-Gas 1:24 .450 Bushmaster AR-15 Freefloat Keymod Pistol Full Build Kit

The Hammer Forge is a .450 Bushmaster AR-15 Full Build Kit built around a compact 10.5-inch carbine-length gas platform. The kit centers on a 10.5-inch Bear Creek Arsenal HBAR profile 4150 steel barrel with a phosphate finish, 1:24 twist rate, and 5/8x32 thread pitch, paired with a KAK .458 compensator and a black crush washer. A micro low-profile steel gas block at 0.750 diameter and a carbine-length stainless steel gas tube are included on the front end. The upper receiver is a Panhead billet aluminum design configured for .458 SOCOM and .450 Bushmaster with an enlarged .458 ejection port door installed and an ejection port door, rod, and spring included, paired with a 10-inch ultra-slim freefloat Keymod handguard in black. A complete .458 SOCOM and .450 Bushmaster compatible bolt carrier group in black nitride 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 with a fire control group and a Mil-Spec A2 pistol grip in black, a Mil-Spec heavy-duty 6-position black aluminum carbine buffer tube, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, an AR-15 M16 Mil-Spec end plate, and an AR-15 carbine castle nut. The Magpul BTR fixed-length pistol stabilizing brace in black reinforced polymer, compatible with standard Mil-Spec carbine buffer tubes, is included. Lower receiver not included.

Key Features

• 10.5-inch Bear Creek Arsenal HBAR profile 4150 steel barrel, phosphate finish, 1:24 twist, 5/8x32 thread pitch, .450 Bushmaster
• Carbine-length gas system
• Carbine-length stainless steel gas tube
• Micro low-profile steel gas block, 0.750
• KAK .458 compensator, 5/8x32, black crush washer included
• Panhead billet aluminum upper receiver, .458 SOCOM and .450 Bushmaster compatible, enlarged .458 ejection port door installed, ejection port door, rod, and spring included
• 10-inch ultra-slim freefloat Keymod handguard, black
• Complete .458 SOCOM and .450 Bushmaster bolt carrier group, black nitride finish
• Mil-Spec AR-15 M4 charging handle
• Complete Mil-Spec AR-15 lower parts kit, fire control group included, Mil-Spec A2 pistol grip, black
• Mil-Spec heavy-duty 6-position black aluminum carbine buffer tube
• Standard carbine buffer, 3 oz
• Standard AR-15 carbine recoil spring, made in USA
• AR-15 M16 Mil-Spec end plate
• AR-15 carbine castle nut
• Magpul BTR pistol stabilizing brace, black reinforced polymer, fixed-length design, Mil-Spec carbine buffer tube compatible

Perfect For

• Builders sourcing a compact .450 Bushmaster AR-15 pistol full build kit with a Panhead billet upper receiver, Bear Creek Arsenal HBAR barrel, KAK .458 compensator, black nitride BCG, and Magpul BTR brace already included, pairing it with their own lower receiver
• Shooters building a 10.5-inch .450 Bushmaster carbine-gas pistol platform who want the BCG, charging handle, Mil-Spec carbine buffer tube, and Magpul BTR fixed-length brace covered in one kit with an ultra-slim freefloat Keymod handguard
• AR-15 pistol builders who want a .450 Bushmaster pistol full build kit with a Panhead billet upper receiver featuring an enlarged .458 ejection port and a complete Mil-Spec buffer system without sourcing components separately

Barrel and Muzzle Device

The 10.5-inch Bear Creek Arsenal HBAR profile barrel is chambered in .450 Bushmaster and constructed from 4150 steel with a phosphate finish. The twist rate is 1:24 and the thread pitch is 5/8x32, which matches the included KAK .458 compensator. A black crush washer, a micro low-profile steel gas block at 0.750 diameter, and a carbine-length stainless steel gas tube cover the front end gas configuration on this carbine-length platform.

Panhead Billet Upper Receiver and Handguard

The Panhead billet aluminum upper receiver is configured for .458 SOCOM and .450 Bushmaster with an enlarged .458 ejection port door installed. An ejection port door, rod, and spring are included. The 10-inch ultra-slim freefloat Keymod handguard is black with Keymod attachment points along the body for accessory mounting. These two components define the exterior structure of the upper assembly on this .450 Bushmaster pistol platform.

Bolt Carrier Group and Charging Handle

The complete bolt carrier group carries a black nitride finish and is compatible with .458 SOCOM and .450 Bushmaster. 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 and includes a fire control group and a Mil-Spec A2 pistol grip in black. The buffer system includes a Mil-Spec heavy-duty 6-position black aluminum carbine buffer tube, a standard 3 oz carbine buffer, a USA-made standard AR-15 carbine recoil spring, an AR-15 M16 Mil-Spec end plate, and an AR-15 carbine castle nut. The Magpul BTR fixed-length pistol stabilizing brace in black reinforced polymer pairs with the included Mil-Spec carbine 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.