TacFire Pistol Upper Assembly — 9mm Luger, 4" Black Nitride Barrel, 7075-T6 Receiver, M-LOK® Handguard — AR-Platform (BU9MM4 | UPC 729205520242)
Build a compact, soft-shooting AR-pattern 9mm without the parts scramble. The TacFire BU9MM4 Pistol Upper Assembly pairs a 4" black nitride barrel with a rugged, black-anodized 7075-T6 aluminum receiver and a slim free-float M-LOK® handguard for modern accessory mounting. Optimized for 9mm Luger pistol builds, this upper gives you the durability, modularity, and maneuverability you want for CQB-style training, home/ranch setups, and range fun—while keeping weight and length to a minimum.
Why Choose the TacFire BU9MM4 Upper?
Ultra-Compact 4" Barrel: Excellent balance and handling for confined spaces, vehicle classes, and suppressor-centric builds (where legal).
Black Nitride Durability: The nitride treatment hardens the bore and exterior for improved corrosion resistance and easy cleanup.
7075-T6 Forged Receiver: Stronger than 6061, the receiver resists flex and holds zero with optics and irons.
Free-Float M-LOK® Handguard: Mount lights, handstops, and QD sling cups while keeping the barrel free for consistent POI.
AR-Platform Ergonomics: Familiar controls, endless accessory ecosystem, and straightforward mating to a compatible 9mm lower.
Key Features & Specs
Model / Part: BU9MM4
UPC: 729205520242
Caliber: 9mm Luger (9×19)
Barrel: 4", black nitride finish, threaded muzzle (common 9mm threads are 1/2×28 or 1/2×36—verify exact pitch before buying a device)
Receiver: 7075-T6 aluminum, black anodized
Handguard: Free-float M-LOK®, slim/ventilated for heat management and cable routing
Operating Style: 9mm AR builds are typically straight blowback (check your lower/bolt system for compatibility)
Bolt Carrier Group / Charging Handle: Varies by lot—some packages are upper-only; confirm retailer’s bill of materials
Muzzle Device: Not always included—verify listing before purchase
Performance You’ll Notice
Smooth, Fast Handling: The 4" configuration keeps overall length tight for quicker transitions and easier storage.
Low-Maintenance Running: Nitride surfaces resist fouling and wipe clean—great for high-volume 9mm range sessions.
Accessory-Ready: M-LOK® slots at 3/6/9 (and often 45°) accept lights, pressure pads, and handstops without adding bulk.
Free-Float Consistency: Isolating the handguard from the barrel helps maintain point of impact when bracing or using a sling.
Ideal Use Cases
Home & Property Training: Short OAL and controllable recoil (use proper hearing/eye protection).
Range / PCC Practice: Economical 9mm ammo and AR ergonomics make skill work more affordable.
Truck/Pack Projects: Lightweight, compact top end that’s easy to transport and stage.
Suppressed Builds (where legal): Short barrel leaves room for muzzle devices and suppressor mounts—always verify thread pitch and follow manufacturer torque specs.
Compatibility & Build Notes
Lower Receiver: Requires a 9mm-pattern AR lower or mag block system (e.g., Glock-pattern or Colt-pattern). Ensure your bolt, magazines, and lower are all the same pattern.
Bolt / Buffer System: Use a 9mm-specific BCG and a 9mm-appropriate buffer/spring; blowback setups often benefit from heavier buffers to tune ejection.
Magazines: Choose quality mags that match your lower (Glock-pattern or Colt-style).
Optics & Sights: Add a micro red dot and/or BUIS on the top rail; confirm co-witness height with your preferred mount.
Muzzle Devices: Confirm thread pitch before installing a brake, flash hider, or suppressor mount; re-torque and re-zero after changes.
Setup Tips (Non-Instructional)
Lube & Inspect: Lightly oil contact points; check handguard, gas-block (if present on your variant), and barrel nut fasteners for torque/Loctite per manufacturer guidance.
Function Test: Verify last-round bolt hold-open with your mags; tune buffer weight if ejection is erratic.
Zero Smart: A 25- or 50-yard zero is practical for 9mm ARs; confirm holds at your typical training distance.
Cable Management: Use M-LOK® clips or channels to secure pressure pads and avoid snags.
Legal & Safety Reminder
Know your federal, state, and local laws regarding AR-pistol configurations, barrel length, braces/stocks, suppressors, and transport. Configure and use your build in full compliance with current regulations.
What’s in the Box*
TacFire BU9MM4 9mm Pistol Upper — 4" black nitride barrel, 7075-T6 black-anodized receiver, free-float M-LOK® handguard
*BCG, charging handle, and muzzle device may or may not be included—confirm the seller’s BOM before checkout.
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TacFire Pistol Upper Assembly — 9mm Luger, 4" Black Nitride Barrel, 7075-T6 Black-Anodized Receiver, M-LOK® Handguard (BU9MM4 | 729205520242): a compact, durable, and accessory-ready top end that brings AR ergonomics to budget-friendly 9mm training and compact defensive builds.
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