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7.5" 300 BLACKOUT AR-15 BARRELED UPPER - MAS DEFENSE MW8 OCTAGON 9.87" M-LOK RAIL
7.5" 300 BLACKOUT AR-15 BARRELED UPPER - MAS DEFENSE MW8 OCTAGON 9.87" M-LOK RAIL
 
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MSRP: $430.00
Our Price: $339.99
SALE PRICE: $304.99

Price with Selected Options: $304.99

Stock Status: In Stock


Product Code: MAS-073B1-MDOC-10

Upper Receiver Options:


Barrel Options:


Handguard Options:


Gas Block Options:


Gas Tube Options:


Muzzle Device Options:


***ON SALE - Choose a Bolt Carrier Group:


***ON SALE - Choose a Charging Handle:



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DESCRIPTION
 
7.5" 300 BLACKOUT AR-15 BARRELED UPPER - MAS DEFENSE MW8 OCTAGON 9.87" M-LOK RAIL

The options listed below come standard with this barreled upper. The drop down options listed above allow you to customize your build. You can leave them as is, change one option or change them all! We let you build your upper the way you want it built!

1. Upper Receiver - 7075 T6 Aluminum A4. Precision Machined to Mil-Spec Tolerances. Black Hardcoat Anodized Mil-Std-171 Type III. M4 Ramps, Forward Assist, Ejection Door.

2. Barrel - 7.5" 300 BLK 1X7 MAS DEFENSE GOVT PROFILE 4150V MELONITE - MAS00124106

3. Handguard - MAS Defense MW8 Octagon 9.87" M-LOK Rail - (ID 1.8")

4. Gas Block - .750 Low Profile Steel Melonite Nitride Treated Gas Block

5. Gas Tube - Pistol Length Stainless Steel Gas Tube

6. Muzzle Device - Flash Can

Bolt Carrier Groups and Charging Handles are sold separately.

All barreled uppers are head spaced and test fired to ensure function.

ALL LAWS APPLY. IT IS THE RESPONSIBILITY OF THE BUYER TO UNDERSTAND ALL LAWS REGARDING PURCHASE AND OWNERSHIP OF THIS UPPER. WE STRONGLY URGE YOU TO CONTACT YOUR LOCAL FFL AND/OR THE ATF WITH ANY AND ALL QUESTIONS TO MAKE SURE YOU UNDERSTAND THE LAW BEFORE PURCHASING THIS ITEM.

***80% LOWERS CANNOT BE PURCHASED WITH BARRELED UPPERS OR BUILD KITS. ORDERS THAT INCLUDE THEM WILL BE CANCELLED AND CHARGED A 15% CANCELLATION FEE***.

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Average Rating: Average Rating: 5 of 5 5 of 5 Total Reviews: 2 CLICK HERE TO WRITE A REVIEW »

  0 of 0 people found the following review helpful:
 
5 of 5 Quality start to finish August 15, 2025
: Jeremy Wilkins from Shawnee, OK United States  
The attention to detail from the website layout to the ordering process to the parts themselves are a huge ease of mind. High quality parts and the value are all I have found through Mas Defense, I’ve already put mine through abuse that most all others would have already faltered (and have) by now and not one single issue whatsoever!

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  0 of 0 people found the following review helpful:
 
5 of 5 Awesome customer service and fast fulfillment June 23, 2025
: Dan B  
I’ll definitely come back to MAS Defense for future purchases. They were able to add an item to their assortment to fit just what I was looking for without having to go through a custom order process. Looking forward to running this upper for years to come.

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