The TacFire BU-556-16 Complete Upper Assembly in 5.56x45mm NATO provides a ready-to-install solution for building or upgrading an AR-15 rifle with reliable performance for training, competition, and defensive applications. This complete upper features a 16 inch Black Nitride barrel, 7075-T6 aluminum receiver, 15 inch M-LOK free float handguard, and includes a bolt carrier group for shooters seeking versatile capability with standard AR-15 magazines and components.
Key Features
- Manufacturer Part Number: BU-556-16
- Caliber: 5.56x45mm NATO, also accepts .223 Remington
- Barrel Length: 16 inches, 4150 Chrome Moly Vanadium steel with Black Nitride finish
- Barrel Twist Rate: 1:8
- Barrel Thread: 1/2x28 with A2 style flash hider
- Gas System: Carbine length with low profile gas block
- Upper Receiver: 7075-T6 forged aluminum with Black Anodized finish
- Handguard: 15 inch M-LOK free float rail with Black Anodized finish
- Bolt Carrier Group: Included
- Charging Handle: Included
- Forward Assist: Installed
- Ejection Port Cover: Installed
- UPC: 686294505850
Special Features
- Complete upper assembly includes all components needed except lower receiver for immediate installation
- Black Nitride barrel finish provides superior corrosion resistance and reduced friction compared to phosphate coatings
- M-LOK handguard accepts direct mount accessories without bulky rail sections for weight savings and ergonomics
- Free float handguard design eliminates contact with barrel for improved accuracy potential
- 1:8 twist rate stabilizes bullets from 55 grain to 77 grain across full ammunition range
- Carbine length gas system provides reliable cycling with standard and defensive ammunition
- 1/2x28 threading accepts most 5.56 suppressors and muzzle devices without adapters
- Forged 7075-T6 aluminum receiver provides mil-spec strength and accepts all standard AR-15 components
- Low profile gas block fits under free float handguard for clean appearance and snag-free operation
- Full length Picatinny top rail accommodates any optic from red dots to magnified scopes
Practical Benefits
- 5.56 NATO chambering accepts both military specification 5.56 and commercial .223 Remington ammunition for maximum versatility
- 16 inch barrel meets legal rifle length requirements while providing optimal velocity for 55 to 77 grain bullets
- Included bolt carrier group eliminates need to source separate components for complete build
- M-LOK mounting system allows attachment of lights, grips, and bipods at preferred positions for competition or tactical use
- Free float design improves accuracy for precision shooting at 100 to 300 yards on targets or game
- Carbine length gas system ensures reliable function with wide range of commercial and military ammunition
- Black Nitride finish resists corrosion during field use in wet conditions or storage without frequent maintenance
- 1:8 twist stabilizes everything from 55 grain bulk ammunition to 77 grain match projectiles
- Drop-in installation onto any mil-spec AR-15 lower receiver takes minutes with standard tools
- A2 flash hider controls muzzle flash and can be easily replaced with suppressor or compensator
The TacFire BU-556-16 Complete Upper Assembly 5.56x45mm NATO is a solid fit for shooters building a versatile AR-15 platform capable of training, competition, hunting, and defensive applications.
| MANUFACTURER | TACFIRE |
| CALIBER | 5.56MM |