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GM-M15 20" M16 A1 5.56mm 1:12 twist


Product Description

5.56mm, 1:12 twist, 20", 41V50 steel, , weighs 1.75 lbs., fully machined and assembled with M16 extension, chrome line bore and chamber, drilled gas port, phosphate finish, button rifled, air gauged, stress relieved. 1960s era pencil profile, muzzle threading 1/2 x 28.  

Barrel is not pinned for front site.

Under "See 1 more picture" there is a detailed drawing of this barrel. 

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Product Reviews

Showing reviews 1-5 of 80 | Next

  1. Appears to be as good as it gets 5 Star Review

    Posted by on 19th Aug 2020

    After reading reviews I choose GM barrels for My M16a1 replica. Friendly and good to work with, they sent Me a fine barrel that meets all my expectations.

  2. Great product great service 5 Star Review

    Posted by on 10th May 2020

    The barrel is first rate in every way. Completely meets the standard for my retro build.

  3. High Qualiy Barrel 5 Star Review

    Posted by on 17th Apr 2020

    I have purchased many barrels from Green Mountain Barrel. They manufacture the best in the industry. Their shipping is super fast, and customer service is fantastic. Thanks again GMB for providing the best quality barrels !


  4. accurate. 5 Star Review

    Posted by on 23rd Jul 2019

    I’ve free floated this barrel in a MI combat rail, and it achieves consistent near MOA performance with Federal xm193 55gn. 1 7/8” at 200 yards, 3 1/4” at 300 yards, and 4 1/2” at 400 yards ( consistent 5 shot groups). Top quality performance for plain military ball nearly makes hand loading unnecessary. A true testament to quality.

  5. Exactly what I needed 5 Star Review

    Posted by on 3rd Jun 2019

    I used this to complete an old demilled M16A1 parts kit. For this purpose it is perfect. It functions reliably and is more accurate than me with iron sights. To those asking about why there are no cuts for taper pins the answer is because it is not standardized exactly where those cuts go. New FSBs come without holes and old parts kits FSBs come with holes that are not going to be in exactly the same place as any other given FSB. All you need to make the cuts is a drill press and a taper reamer for making it tapered after drilling. I recommend putting the reamer in a tap wrench and reaming by hand rather than using the press. You will need to get oversized pins for building a demilled parts kit that already has holes in the FSB.

Showing reviews 1-5 of 80 | Next