Loading... Please wait...

Like Us on Facebook!


Add to Wish List

Click the button below to add the GM-M8 16" Mid Length gas system 5.56 mm to your wish list.

You Recently Viewed...

GM-M8 16" Mid Length gas system 5.56 mm

Calculated at checkout

Product Description

5.56mm, 1:8 twist,16", 41V50 steel, weighs 1.9 lbs., mid length gas system, chrome line bore and chamber, phosphate finish, button rifled, stress relieved, air gauged, gas port, assembled with M4 extension with M4 feed ramps, muzzle thread 1/2 x 28. 

Barrel is not pinned for front site.

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

Write your own product review

Product Reviews

Showing reviews 1-5 of 62 | Next

  1. recce build 5 Star Review

    Posted by on 15th May 2019

    fantastic quality,fantastic price,GM is without a doubt your ace in the hole fore barrels ,these barrels absolutely can ,and do compete head to head with barrels on the market that are priced far higher.the best customer service hands down.

  2. Barrel review 5 Star Review

    Posted by on 8th May 2018

    Very well made.......installed perfectly.

    Quality product IMHO.

  3. A good inexpensive barrel 5 Star Review

    Posted by on 19th Mar 2018

    While expensive good barrels are easy to find, trying to find a good barrel under, say- the $200 price point is not so easy, as I found out. I ordered what appeared to be a good barrel from a large eBay supplier only to have the barrel fail headspace check- and its replacement as well! My local gunsmith recommended Green Mountain as their go-to source for people looking for affordable barrels, and I'm very happy with this purchase!
    Besides, I know they've been around a long time, having ordered a barrel from them back in the '70's!

  4. As good a barrel as you can get at a very fair price 5 Star Review

    Posted by on 14th Mar 2018

    First off I'm in law enforcement and I'm extremely picky. If a rifle wont shoot 1" groups at 100 yards I don't even want to mess with it. I ordered my first Green Mountain barrel for an AR-15 SBR. It was their 10" barrel and I was blown away by it's accuracy. It shot right at 1" groups at 100 yds with 62gr Lake City Green tip!!!! I couldn't believe it and was absolutely not expecting that. It shoots .5" to .75" groups with a hand loaded Sierra Match bullet and I'm sure it's capable of more if I took the time to refine the load. I've recommended these barrels to several other friends and fellow officers and they have had the same experience I have had. We just ordered four 16" barrels for some upcoming AR-15 projects and I know they won't disappoint. Do Not go spend crazy money on "high end" over priced barrels. These Green Mountain barrels are "high end" in my opinion without that "high end" price. Customer for life!!!!!

  5. Green Mountain does it again! 5 Star Review

    Posted by on 7th Mar 2018

    This is my second Green Mountain barrel and I could not be happier. The first was a bull barrel for my 10/22. Amazing quality and an incredible value. I decided to go with them for this build since I was so pleased with my first purchase. Once again I have zero regrets and absolute faith in the quality of this company’s workmanship. After all they’ve been making rifle barrels as long as I’ve been alive.
    I just couldn’t wait to get this puppy to the range. I was really there primarily to test the function of the rifle. All went well and I was also happy to see how well she was grouping. Unfortunately I don’t have any specific or long term experience to report, but I’ll be glad to update the review as I put more rounds through this barrel. I will say it was nice touch to receive a letter from GM thanking me for my purchase, reminding me that I made a solid choice. Thank you GM and I’ll certainly be patronizing your site for years to come.

Showing reviews 1-5 of 62 | Next