MK3 - 14.5" P&W 5.56 Complete Upper Receiver - Pinned Gas Block

The MK3 is our 3rd custom upper in a 14.5" variant. I saved a few uppers from being pinned and welded to give some people options for other muzzle devices in the future. Feel free to inquire about specific muzzle devices or configurations you would like to order. These are Do-It-All uppers build to be extremely accurate, reliable, and affordable. First rebarrel is still free and every component has a lifetime warranty.


Each upper ships with a unique checklist noting the ejection pattern with brass cased ammunition, function, lock back on empty, and any buffer/spring recomendations I may have.


The Basics


14.5" Ballistic Advantage 5.56 Upper With Pinned & Welded VG6 Flash Hider, 13.7" Breek Arms Mlock Rail, Toolcraft NiB BCG, Pinned Gas Block, Mil-Spec Upper and Charging handle


The Specifics



Manufacturer - Ballistic Advantage

Length/Chamber - 14.5" 5.56

Twist - 1:7 Twist

Material - 4150 Chrome Moly-Vanadium

Profile - Government

Gas System - Mid-Length

Finish - Nitride

Thread Pitch - 1/2x28

Gas Port - .081


*Gas Blocks Are Pinned*

1st Rebarrel - FREE


All NFA/ATF Rules Apply


Ballistic Advantage makes good stuff and these are no different. The 14.5" Performance series is gassed perfectly with a .081" gas port on the midlength gas system. Recoil is negligible and ejection and extraction is strong and consistent. I recommend a standard carbine spring and buffer as these are gassed right in the sweet spot so nothing special is required, though you can always tune to your desired feel. These are very accurate barrels, I expect around 2MOA accuracy with good ball ammo and 1 MOA or better with good match loads.


Barrel nut is sequentialy torqued down to 50 FT-lbs. Starting at 25, then 35, and then finally 50 FT-lbs to ensure proper mating of the threads. 


If you legit burn out a barrel, like 10,000 -25,000 rounds, and the barrel becomes inaccurate I will rebarrel it for you for free. Good luck.



Bolt Carrier Group:

Manufacturer -Toolcraft

Bolt Material - 9310 Alloy

Carrier Material - 8620 Alloy

Gas Key Material - 4130 Alloy

Profile - Full Auto

Finish - NiB

Gas Key Screws - Grade 8 (torqued and staked to Mil-Spec)

Forward Assist Cuts

Mil-Spec Firing Pin (Hard Chrome Coated)



Manufacturer - Breek Arms

Length - 13.7"

Material - 6061 T6 Aluminum

Finish - Hard Coat Black Anodization

Mounting Platform - Mlock

Wedge Lock Attachment


Barrel nut torqued to 50 FT-lbs

Wedge Lock Tightened Down to 60 IN-lbs with Blue Loctite


Upper Receiver:

Manufacturer - Anderson

Material - 7075 T6 Aluminum

Machined from Forged Aluminum

Finish - Type 3 Hardcoat Anodized Black

Standard Forward Assist

Standard Dust Cover

M4 Feed Ramps

NOT T-Marked, if you care...


Nothing special here, everything is Mil-Spec (standard), which is the way that I like it for an upper receiver.


Charging Handle:

Material - 7075 T6

Machined from Forged Aluminum

Finish - Type 3 Hardcoat Anodized + Teflon Coated for Smoother Operation


Same here, standard and boring. High quality, high strength, enough said.


Gas Block:

Material - 4140 Steel

Finish - Nitride

Style - Low Profile

Size - .750"

Attachment Method - 2x Set Screws


Dimpled Barrel

Not Adjustable


You shouldn't really notice a good gas block and this one is no different. High quality steel that's as tough as the barrel for longevity. Rear set screw fits into the dimple on the barrel, ensuring proper alignment and that the gas block won't shift on you.


Set screws are torqued to 30 IN-lbs. and have High-Temp threadlocker applied for extra security.


Gas Tube:

Length - Rifle

Material - Stainless Steel

Finish - Black Nitride


It's a stainless steel gas tube held in place with a roll pin, what more do you want?


Muzzle Device


VG6 Gamma Flash Hider

Finish - Black Nitride

Thread - 1/2x28


***any muzzle device you want can be substituted for an additional cost*** 


When Pinned and Welded in place this will bring the MK3 to a legal 16"+ If you do not want it pinned please write that down in the order notes!


If you have any questions or requests please leave them in the order notes!


MK3 - 14.5" P&W 5.56 Complete Upper Receiver - Pinned Gas Block

Out of Stock
  • Our stated policy is to not accept returns, but if you accidently ordered the wrong item or there was a mistake or if you have any issue at all send us an email (listed in the "contact us" section) and we will work it out.