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GM-M51 16" M4 Barrel Assembly 1:7 twist

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Product Description

5.56 mm, 1:7 twist, 16" long, 41V50 steel, weighs 2.0 lbs, button rifled, air gauged, stress relieved,  it is already assembled with an A2 Front sight Base, Post, Detent, and Spring, a Handguard cap, and Barrel Nut. The GM-M51 sports a Carbine Gas length, M4 Feed ramps, chrome line bore and chamber,  phosphate exterior coating.

For a Limited Time, the NEW GM-M51!

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Product Reviews

Showing reviews 1-5 of 10 | Next

  1. 16 in m-4 barrel 5 Star Review

    Posted by on 10th Apr 2019

    Barrel installed with no issues and headspaced perfectly. Took to the range and zeroed in 9 rounds. Accuracy was phenomenal at 100 yards! My first green mountain rifle barrel and certainly not the last!

  2. Flawless, no, perfect! 5 Star Review

    Posted by on 28th Nov 2018

    For that mil-spec build, you cannot go wrong with this barrel. Only wish GMB offered this in the 20 inch govt profile barrel. That would be awesome!

  3. BEST BARRELS EVER 5 Star Review

    Posted by on 2nd May 2018

    Seriously these are the best barrels for the price I've ever used. I bought this barrel for a deployment build and I was slapping steel at 600 yards with 62 gr green tip and an aimpoint pro so easily it got boring. Don't worry about buying high dollar barrels, these are great.

  4. GM-M51 5 Star Review

    Posted by on 2nd Apr 2018

    This is my third barrel from Green Mountain. They just do a fantastic job. Very well packed for shipping. Great accuracy and function. I like the phosphate finish-it just looks like it belongs on an AR15. Very pleased. Good value, nothing else to say, "keep up the GOOD WORK"-I will be a customer for life. Thanks Again.

  5. Follow up 5 Star Review

    Posted by on 22nd Mar 2018

    I purchased this barrel 08/17 and after a few thousand rounds decided to do a follow up review.
    The barrel has performed perfectly. The important things like accuracy and durability has been exceptional. Will I buy another...Absolutely. I gave it 5 stars because as a trusted barrel, it is, M4 feed ramps were perfectly aligned and the head-spacing was perfect with my bolt.
    As a former Marine and a 25 year retired LEO, I don't gamble with faith or luck, my build was purely for home defense, the protection of my family. So of course I went with quality, not hype.
    The only two things I would change, for what my opinion is worth, is an "F" marked FSB, I had to order a .040 height sight post to sight in with my
    MBUS, and the second really minor bitch...The engraving on my barrel was double and lightly stamped, (5.56 NATO) so it was unreadable.

Showing reviews 1-5 of 10 | Next