Davidson Defense Thumper 5" 45ACP AR-45 Pistol Build Kit, M-Lok Handguard, 1:16, SBR Ready

Thumper SBR Ready 5-Inch 1:16 .45 ACP AR-45 M-LOK Handguard Pistol Full Build Kit

The Thumper SBR Ready Full Build Kit is built around a 5-inch .45 ACP direct blowback barrel with a Vertex Enhanced pistol-caliber billet upper receiver, a 4.2-inch tubular M-LOK handguard, and a complete PCC bolt assembly and charging handle. Lower receiver is not included, and this kit ships without a brace.

Key Features

• SBR Ready design
• 5-inch .45 ACP barrel, slim profile, 4150 CrMoV steel, 1:16 twist, Parkerized finish
• Direct blowback operating system
• Vertex Enhanced pistol-caliber AR-15 billet upper receiver, black, integrated Picatinny top rail
• 4.2-inch tubular M-LOK aluminum handguard, black, 1.77" internal diameter, suppressor-ready
• AR-15 .45 ACP birdcage muzzle brake, Manganese Phosphate finish, with 5/8-inch black crush washer
• PCC AR bolt assembly for .45 ACP and mil-spec quality M4 charging handle included
• Complete mil-spec AR-15 Lower Parts Kit and buffer-system components included
• Lower receiver is not included.

Barrel and Operating System

The 5-inch .45 ACP barrel is machined from 4150 chrome moly vanadium steel in a slim profile with a Parkerized finish and a 1:16 twist. This build runs a direct blowback operating system rather than a gas-driven cycle. The muzzle carries an AR-15 .45 ACP birdcage muzzle brake finished in Manganese Phosphate on 37/64x28 threads, secured with the included 5/8-inch black crush washer.

Upper Receiver and Handguard

The upper receiver is a billet aluminum unit built for the pistol-caliber AR-15 platform, finished in black with an integrated Picatinny top rail. It's paired with a 4.2-inch tubular M-LOK handguard machined from aluminum, finished in black, with a 1.77-inch internal diameter and a suppressor-ready design.

Bolt Assembly and Charging Handle

The kit includes a PCC AR bolt assembly built for .45 ACP, along with a mil-spec quality AR-15 M4 charging handle.

Lower Parts Kit and Buffer System

The kit includes a complete mil-spec AR-15 Lower Parts Kit with an A2-style pistol grip and full fire control group, along with the carbine castle nut and mil-spec receiver end plate. The buffer system pairs an AR-15 9mm carbine buffer with a USA-made standard AR-15 carbine recoil spring, cycling inside a heavy-duty mil-spec AR-15 six-position carbine buffer tube.

SBR Ready

This kit ships without a brace. It's built for customers who plan to finish their configuration on their own terms, so review the included component list above as supplied. This description does not represent a finished or ready-to-use firearm.

Follow all manufacturer instructions and safe handling practices.

Ensure compliance with all applicable federal, state, and local laws.

Lower receiver is not included.

Ships without a brace.

Do not attach a stock unless the resulting configuration complies with all applicable federal, state, and local laws.