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MK5 - 12.3" 5.56 Complete Upper Receiver - Hanson Barrel

The MK5 is our last upper for the MK series of uppers, with more improvements to the overall build. 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  ammunition, function, lock back on empty, and any buffer/spring recomendations I may have.


The Basics


12.3" Ballistic Advantage Hanson 5.56 Upper, 9.8" KAK 7-Sided Mlock RAill, AO Precision TMS BCG, Mil-Spec Upper and Charging handle


The Specifics



Manufacturer - Ballistic Advantage

Length/Chamber - 12.3" 5.56

Twist - 1:7 Twist

Material - 4150 Chrome Moly-Vanadium

Profile - Hanson

Gas System - Carbine

Finish - Nitride

Thread Pitch - 1/2x28

Gas Port - .072

*Pinned Gas Blocks*


1st Rebarrel - FREE


All NFA/ATF Rules Apply


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:

MFG: AO Precision

Bolt Material - C158 Alloy

Carrier Material - 8620 Alloy

Gas Key Material - 4130 Alloy

Profile - Full Auto

Finish - Phosphate/Chrome

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

Forward Assist Cuts

Mil-Spec Firing Pin (Hard Chrome Coated)



Manufacturer - KAK

Length - 9.8"

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

MK5 - 12.3" 5.56 Complete Upper Receiver - Hanson Barrel

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.

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