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TacFire .300 Blackout Complete M-LOK Upper Assembly Up to $20.00 Off w/ Free S&H — 3 models

TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 10in, Type III Hard Anodized, Black, Large, BU-3008-10
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 16in, Type III Hard Anodized, Black, Large, BU-300-16
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8
1 of 3 images
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 10in, Type III Hard Anodized, Black, Large, BU-3008-10
2 of 3 images
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 10in, Type III Hard Anodized, Black, Large, BU-3008-10
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 16in, Type III Hard Anodized, Black, Large, BU-300-16
3 of 3 images
TacFire Complete M-LOK Upper Assembly, .300 Blackout , 16in, Type III Hard Anodized, Black, Large, BU-300-16

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Questions & Answers
Is this upper approved for full auto? Manufacturer Answer

All of our BCG's and receivers are capable of full auto. We do not recommend prolonged usage due to barrel overheating / warping of chamber

by TACFIRE INC., Manufacturer, May 13, 2026
is the gas block adjustable? Manufacturer Answer

We use a standard non-adjustable .750 gas block

by TACFIRE INC., Manufacturer, April 1, 2026
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
300Blk upper by Phantom, Verified Owner, March 22, 2024
Good product, great price, complete with bolt carrier group and charging handle. Excellent fit on the receiver. Will be buying a 6.5 Creedmoor upper when it becomes available. Great job Optics Planet.
1/1 found this helpful
Most Recent Reviews
Ran it with my 5.56 lower no problem. Very mobile and fun gun. by Wahoo, Verified Owner, June 15, 2026
Great deal Ran it with my 5.56 lower no problem. Very mobile and fun gun.
Most Recent Reviews
300 blackout by nic, Verified Owner, March 13, 2026
Looks great, no issues with shipping or operation. Will definitely buy again
Read All 3 Reviews

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ATTENTION! We currently do not ship this product to P.O. Boxes, AK, CA, CT, DE, HI, MA, NJ, NY, U.S. Territories, or select Colorado locations. Please see our policies for more information or a detailed list of locations.

made-in-usa-flag Made in USA

Help support American manufacturing! Marked models of this product have gone through rigorous review and been certified by the manufacturer as Made in the USA.

Product Info for TacFire .300 Blackout Complete M-LOK Upper Assembly

If you're browsing for a great bargain for the TacFire .300 Blackout Complete M-LOK Upper Assembly, then you've arrived at the absolute correct place..image

Formulated by using several of the most extremely durable and long lasting materials in existence, these AR15 Upper Receivers through TacFire will present you with something that will give a great deal of consistency.

TacFire has been generating high quality merchandise for a number of years, and the TacFire .300 Blackout Complete M-LOK Upper Assembly is their way of revealing just how much they care.

At OpticsPlanet, we ensure that it is our responsibility to receive the perfect solution for all your requirements, and exhibiting the TacFire .300 Blackout Complete M-LOK Upper Assembly is a thing that we are pleased to offer.

WARNING: California`s Proposition 65

Specifications for TacFire .300 Blackout Complete M-LOK Upper Assembly:

Manufacturer: TacFire
Caliber: .300 AAC Blackout
Barrel Profile: Government
Gas System Length: Pistol Length
Barrel Twist Rate: 1-8
Firearms Threads Per Inch: 5/8x34
Handguard Type: Free-Float
Muzzle Device: A2 Flash Hider
Finish: Type III Hard Anodized
Color: Black
Gas Block Journal Size-Diameter: .075 in
Gun Rail: M-LOK
Barrel Material: 4150 Chrome Moly Vanadium
Bolt Carrier Group Included: MIL-SPEC
Charging Handle Included: MIL-SPEC
Magazine Included: No
Condition: New
Mount Type: M-LOK
Country of Origin: USA

Features of TacFire .300 Blackout Complete M-LOK Upper Assembly

  • Mil-Spec upper receiver chambered in .300 Blackout with A2 flash hider

Package Contents:

  • TacFire .300 Blackout Complete M-LOK Upper Assembly
  • Bolt Carrier Group / Charging Handle

TacFire .300 Blackout Complete M-LOK Upper Assembly Orderable Models

List of Orderable Models

  • TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8 , MPN: BU-300-8 , UPC: 729205511387 , Code: 29U-URC-BLUR7-BU-300-8
  • TacFire Complete M-LOK Upper Assembly, .300 Blackout , 16in, Type III Hard Anodized, Black, Large, BU-300-16 , MPN: BU-300-16 , UPC: 729205501050 , Code: 29U-URC-BLUR7-BU-300-16
  • TacFire Complete M-LOK Upper Assembly, .300 Blackout , 10in, Type III Hard Anodized, Black, Large, BU-3008-10 , MPN: BU-300-10 , UPC: 729205508325 , Code: 29U-URC-BLUR7-BU-3008-10

TacFire .300 Blackout Complete M-LOK Upper Assembly Unavailable & Discontinued Models

List of Unorderable Models

  • USED TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8, EDEMO1, Used, Condition Like New , MPN: BU-300-8-EDEMO1 , Code: 29U-URC-BLUR7-BU-300-8-EDEMO1
  • DEMO, TacFire Complete M-LOK Upper Assembly, .300 Blackout , 10in, Type III Hard Anodized, Black, Large, BU-3008-10 , MPN: BU-3008-10-DEMO , Code: 29U-URC-BLUR7-BU-3008-10-DEMO
  • USED, TacFire Complete M-LOK Upper Assembly, .300 Blackout , 8in, Type III Hard Anodized, Black, Large, BU-300-8 , MPN: BU-300-8-EDEMO , Code: 29U-URC-BLUR7-BU-300-8-EDEMO-RE-C
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Last updated 2026-07-01 UTC.