TacFire AR-15 Pistol Build Kit Features The TacFire AR-15 Pistol Build Kit centers on a 7.5 parkerized steel barrel paired with a pistol-length gas system a combination built for reliable function in a compact .300 AAC Blackout pistol build. The included bolt carrier group is chambered for both 5.56 NATO and .300 AAC Blackout giving the builder flexibility if an upper swap is planned down the road. A .750 gas block and pistol-length gas tube are matched to the barrel for proper cycling and a 5/8-24 threaded bird cage A2 muzzle brake manages recoil and muzzle rise at the end of the barrel. The 7 Ultra Slim KeyMod free-float handguard keeps the barrel unobstructed for improved accuracy while offering detachable rail sections for mounting accessories only where needed. Beyond the barrel and upper components the kit includes a full lower parts kit with trigger and hammer a Mil-Spec buffer tube castle nut 3 oz buffer buffer spring and a Mil-Spec charging handle giving the builder nearly everything needed to complete a lower assembly. A standard receiver end plate dust cover and forward assist round out the upper components for a fully functional pistol build. A USA-made pistol grip completes the ergonomics package keeping the build consistent with the kit s domestic manufacturing. For builders assembling a .300 AAC Blackout AR-15 pistol from a single complete parts kit the TacFire AR-15 Pistol Build Kit is for sale at GrabAGun. TacFire AR-15 Pistol Build Kit Specifications Manufacturer: TacFire Model: AR-15 Pistol Build Kit Caliber: .300 AAC Blackout Material: Steel Thread Pattern: 5/8x24 Handguard: 7 KeyMod Free-Float Barrel Length: 7.5 Gas System: Pistol Length Available At: GrabAGun