Davidson Defense Checkmate w/BTR Brace 8.5-inch Pistol-Gas 1:7 556 AR-15 Freefloat M-Lok Handguard Pistol Full Build Kit

Checkmate Magpul BTR Brace 8.5-inch Pistol-Gas 1:7 5.56 NATO AR-15 Freefloat M-LOK Pistol Full Build Kit

The Checkmate is a 5.56 NATO AR-15 Full Build Kit built around a compact 8.5-inch pistol-length gas platform. The kit centers on an 8.5-inch M4 contour barrel with a 1:7 twist rate and 1/2x28 thread pitch, paired with an A2 GI birdcage flash hider and a black 1/2-inch crush washer. A micro low-profile steel gas block at 0.750 diameter and a pistol-length gas tube are included on the front end. The 7075-T6 aluminum anodized upper receiver features M4 feed ramps, a forward assist, and an ejection port door assembly, paired with a 7-inch freefloat M-LOK handguard in black with a partial Picatinny top rail section. A USA-made complete AR-15 bolt carrier group compatible with 5.56 NATO, .223 Remington, .300 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 aluminum carbine buffer tube, a standard 3 oz AR-15 carbine buffer, a USA-made standard AR-15 carbine recoil spring, a Mil-Spec AR-15 M16 receiver end plate, and an AR-15 carbine castle nut. The Magpul BTR pistol brace in black, compatible with standard Mil-Spec buffer tubes, is included. Lower receiver not included.

Key Features

• 8.5-inch M4 contour barrel, 1:7 twist, 1/2x28 thread pitch, 5.56 NATO
• Pistol-length gas system
• Pistol-length gas tube
• Micro low-profile steel gas block, 0.750
• A2 GI birdcage flash hider, 1/2x28, black 1/2-inch crush washer included
• 7075-T6 aluminum upper receiver, anodized, M4 feed ramps, forward assist, ejection port door assembly
• 7-inch freefloat M-LOK handguard, black, partial Picatinny top rail section
• USA-made complete AR-15 bolt carrier group, 5.56 NATO and .223 Remington and .300 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 aluminum carbine buffer tube
• Standard AR-15 carbine buffer, 3 oz
• Standard AR-15 carbine recoil spring, made in USA
• Mil-Spec AR-15 M16 receiver end plate
• AR-15 carbine castle nut
• Magpul BTR pistol brace, black, Mil-Spec buffer tube compatible

Perfect For

• Builders sourcing a complete 5.56 NATO AR-15 pistol full build kit with a 7075-T6 anodized upper receiver with forward assist, 8.5-inch M4 contour barrel, USA-made BCG compatible with multiple calibers, 7-inch freefloat M-LOK handguard with partial Picatinny top rail section, and Magpul BTR brace on a Mil-Spec carbine buffer tube already included, pairing it with their own lower receiver
• Shooters building a compact 8.5-inch pistol-gas 5.56 NATO platform who want the USA-made BCG, charging handle, complete lower parts kit, and Magpul BTR brace covered in one kit with a freefloat M-LOK handguard featuring a partial Picatinny top rail section
• AR-15 pistol builders who want a 5.56 NATO full build kit with a USA-made BCG compatible with multiple calibers and a Magpul BTR brace without sourcing components separately

Barrel and Muzzle Device

The 8.5-inch M4 contour barrel is chambered in 5.56 NATO with a 1:7 twist rate and 1/2x28 thread pitch, which matches the included A2 GI birdcage flash hider. A black 1/2-inch crush washer, a micro low-profile steel gas block at 0.750 diameter, and a pistol-length 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, a forward assist, and an ejection port door assembly. The 7-inch freefloat M-LOK handguard is black with a partial Picatinny top rail section and M-LOK 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 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 aluminum carbine buffer tube, a standard 3 oz AR-15 carbine buffer, a USA-made standard AR-15 carbine recoil spring, a Mil-Spec AR-15 M16 receiver end plate, and an AR-15 carbine castle nut. The Magpul BTR pistol brace in black 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.