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

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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

Previous | Showing reviews 6-10 of 72 | Next

  1. Excellent Barrels! 5 Star Review

    Posted by on 19th Feb 2018

    This is the second barrel I purchased for AR builds. Both performed very well on the range. I would not hesitate to buy another.

  2. Very accurate barrel, great groups 5 Star Review

    Posted by on 23rd Oct 2017

    Used this barrel in a varmint build with a free float handguard and a 3# drop in trigger and am getting 0.544 MOA with handloads using Nosler 40 grain Varmageddon bullets and Benchmark powder with CCI 400 primers. I'm very happy with the accuracy in this highly recommended pencil profile barrel. Bought a second one tip build a retro M16A1 clone, and look forward to seeing what it'll do with drop in handguards and iron sights next.

  3. Great service and product 5 Star Review

    Posted by on 26th Sep 2017

    I think I have purchased three of these barrels from Green Mountain for different builds. These are great barrels for my retro builds. Could not be happier. GM offers great service too.

  4. good stuff 5 Star Review

    Posted by on 17th Aug 2017

    Have not shot it yet been busy with work but it came promptly and I checked it out it is beautiful

  5. Beautiful Bore and Finish 5 Star Review

    Posted by on 27th Apr 2017

    I work for Windham Weaponry, a stone's throw from Green Mountain's facility in New Hampshire. I received the barrel and we went through it with our bore scope to look at the interior. Wow! The free-bore and rifling were perfect and consistent, and the chamber was excellent, no rings, contacts or pitting anywhere! The chrome throughout the chamber and bore was consistent and smooth. I am using this for a retro-build M16A1 look-alike. The only wish I have would be to have the barrel at least cut for taper pins for a .625" gas block. I imagine Green Mountain doesn't do this incase a customer wants to use a low profile gas block with set screws or other styles. Overall, an extremely well made product that I highly advise anyone to use if doing a retro build or using it as a varmint rifle.

Previous | Showing reviews 6-10 of 72 | Next