SKU: 146730
UPC: 729205518300
MPN: BU55610
The TacFire BU-556-10 Pistol Upper Assembly in 5.56x45mm NATO is a complete, ready-to-fire upper receiver designed for AR-platform pistol builds and short-barreled rifle (SBR) configurations. Built for shooters who demand a compact, maneuverable platform without sacrificing reliability or modularity, this assembly combines professional-grade materials with practical field ergonomics. Whether you're building a dedicated home-defense pistol, a truck gun, or a compact training platform, the BU-556-10 delivers the performance of a full-size AR in a drastically shorter footprint.
The upper features a 10-inch black nitride barrel—a military-proven finish that resists corrosion and reduces friction during cycling—paired with a precision-machined 7075-T6 aluminum receiver anodized to mil-spec standards for durability and consistency. The integrated M-LOK handguard provides modern mounting flexibility for lights, lasers, vertical grips, and other tactical accessories without rail weight or snag hazards. The included bolt carrier group is assembled and ready to function; the nitrided steel carrier and chrome-lined bore ensure thousands of reliable rounds downrange. At 4 pounds, this upper balances shootability with control, critical for close-quarters and dynamic shooting disciplines.
This upper assembly is compatible with any AR-15 pistol lower receiver, making it an ideal upgrade for law enforcement trainers, private security professionals, and civilian shooters building or refreshing a defensive platform. Installation requires only the purchase of a matched lower receiver and a few standard gunsmith tools; no proprietary components or special knowledge needed. The 5.56x45mm NATO chambering provides barrier-blind ballistics and ammunition interchangeability with military and commercial loads, ensuring operational flexibility in training or emergency scenarios.
WARNING ⚠️ You must be 18 or older to purchase shotgun or rifle ammunition and 21 or older to purchase handgun ammunition and firearms. Please reference our requirements for ammunition orders to "restricted" states HERE. Always make sure you use the correct ammunition for your firearms. Ammo cannot be shipped to a PO Box. Please reference state & local laws before making a firearm or ammunition purchase.
