Tacfire 7.5" Unassembled Ar 300 Blackout Pistol Build Kit W/ Lower Parts Ki

Build your own 300 Blackout AR pistol with the Tacfire 7.5" unassembled pistol build kit, a complete package designed to get shooters from parts to functional firearm. This kit includes everything needed for a 300 Blackout AR pistol build—upper receiver, lower parts kit, barrel, handguard, bolt carrier group, buffer tube, and grip—making it ideal for builders who want control over their setup without hunting down components individually. Tacfire components are manufactured in the USA, and the kit ships unassembled, giving you hands-on familiarity with your platform from day one.

The heart of this build is a parkerized steel barrel with a 1:7 twist rate optimized for 300 Blackout ammunition, paired with a Krink-style muzzle device threaded 5/8x24—a proven configuration for subsonic and supersonic loads alike. The 7075-T6 billet aluminum upper receiver is stripped and ready for your bolt carrier group, which meets Mil-Spec standards. A slim M-Lok free-float handguard keeps your furniture lightweight while offering mounting options for lights, grips, or rail segments.

Gas management comes via a low-profile gas block and pistol-length gas tube paired with a heavy buffer—a practical setup for the generally lower pressures of 300 Blackout and the compact footprint of a pistol platform. The kit includes a Mil-Spec charging handle with dust cover and forward assist, a complete pistol buffer tube, A2 black pistol grip, and all lower parts required to complete assembly. No smithing expertise required for most of the work, though familiarity with AR assembly is recommended.

This is a builder's kit, not a finished firearm—you'll need to assemble it and comply with all federal and local regulations regarding 300 Blackout AR pistols, including any requirements around barrel length, registrations, or other legal considerations in your jurisdiction.

Key Features

• Complete unassembled kit with upper receiver, lower parts kit, and all core components
• Parkerized steel barrel with 1:7 twist, optimized for 300 Blackout ammunition
• Krink-style muzzle device, 5/8x24 thread
• 7075-T6 billet aluminum upper receiver
• Slim M-Lok free-float handguard
• Mil-Spec bolt carrier group, charging handle, dust cover, and forward assist
• Low-profile gas block with pistol-length gas tube and heavy buffer
• USA-manufactured components
• Includes complete lower parts kit and A2 pistol grip

Specifications

Frequently Asked Questions

What caliber is this kit, and what ammunition does it shoot?

This is a 300 Blackout AR pistol kit. It's chambered for 300 Blackout ammunition, and the 1:7 barrel twist rate is suitable for both subsonic and supersonic loads. The Krink-style muzzle device is threaded 5/8x24 for suppressors or other muzzle devices.

Is this kit legal, and what do I need to know about assembly?

This kit is sold unassembled—you will need to complete the build yourself or have it assembled by a licensed gunsmith. Federal law and your state or local jurisdiction may have specific rules about barrel length, overall length, arm braces, or serialization for AR pistols. Verify all regulations in your area before assembly. The kit includes all major components, but some mechanical aptitude or gunsmithing knowledge is recommended for proper assembly.

What's included in the "complete lower parts kit"?

The kit includes all lower parts needed to complete the build, though specifics beyond the lower receiver, buffer tube, heavy buffer, and A2 pistol grip are not detailed in the product record. We recommend confirming the exact parts list with us before purchase.

Can I use this upper and lower together?

Yes—this is a unified kit designed to work as a matched set. Both the upper receiver and lower parts kit are included and compatible for a 300 Blackout AR pistol build.