Tacfire 16" Unassembled .300 Blackout Rifle Build Kit W/ Lower Parts

The Tacfire 16" .300 Blackout rifle build kit delivers everything you need to assemble a compact, powerful AR-platform rifle from the ground up. This complete unassembled kit includes both upper and lower components, making it ideal for builders who want hands-on control over their firearm and a deep understanding of how it all goes together. Whether you're a first-time builder looking to learn the platform or an experienced gunsmith adding another build to the safe, this kit provides genuine quality parts without forcing you to source components individually.

The upper half features a stripped billet receiver with M4 feed ramps paired to a 7.5" .300 Blackout barrel finished with a .308 5/8x24 TPI spiral fluted flash can and crusher washer. A pistol-length gas system with mil-spec steel tube and pin keeps the action running smoothly, while the ultra-slim 7" M-LOK free-floating handguard gives you a clean platform for your setup. You'll also get a mil-spec charging handle with steel latch, forward assist, and dust cover—all the controls you expect on a professional AR build.

The lower half comes complete with a USA-made lower parts kit, aluminum pistol grip, mil-spec castle nut, and a pistol buffer tube with included 3 oz buffer and spring. The micro/low-profile gas block keeps your sight picture unobstructed. All told, you're getting a thoughtfully spec'd pistol-caliber carbine platform ready for the workbench—no surprises, no missing fasteners.

Key Features

• Complete upper and lower components in one kit—everything needed to assemble
• 7.5" .300 Blackout barrel with spiral fluted design and flash can
• Ultra-slim 7" M-LOK free-floating handguard for clean aesthetics and accessory mounting
• Stripped billet upper receiver with M4 feed ramps
• Pistol-length gas system with mil-spec steel tube
• USA-made lower parts kit with standard controls
• Micro/low-profile gas block for sight-line clarity
• Includes buffer tube, 3 oz buffer, spring, and A2-style grip

Specifications

Frequently Asked Questions

What's included in this .300 Blackout rifle build kit?

The kit includes a complete billet upper receiver, 7.5" barrel with flash can, M-LOK handguard, gas system, charging handle, dust cover, forward assist, stripped lower receiver, lower parts kit, buffer tube, buffer, spring, castle nut, and A2-style grip. You'll need to assemble all components yourself.

Is this kit suitable for a first-time AR builder?

Yes. All components are included and spec'd to work together as a complete system. New builders should reference assembly guides and take their time; understanding how the platform works is part of the appeal of a build kit.

Will this build fit standard AR-15 accessories and optics?

The .300 Blackout caliber uses the standard AR-15 platform, so it accepts M-LOK and rail-mounted accessories. Standard AR-pattern optics mounts (Picatinny) work on the upper receiver as well.

What's the purpose of the 7.5" barrel and flash can?

The short barrel makes this a compact, maneuverable platform ideal for close-quarters or confined spaces. The flash can helps hide muzzle flash and provides a mounting point for sound suppressors at the standard .308 5/8x24 threading.