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GM-M17 20" 5.56x45mm M4 A2, 1:7 twist


Product Description

  • Caliber- 5.56x45mm w/M4 Feed Ramps
  • Twist Rate- 1:7
  • Length- 20"
  • Profile- M4 A2 Under "See 1 more picture" there is a detailed drawing of this barrel.
  • Finish- Chrome Line Phosphate
  • Gas System Length- Rifle
  • Gas Block OD- .750+-(.001)
  • Steel Type- 41V50
  • Thread Pitch- 1/2x28
  • Weight- 2.05lbs

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Product Reviews

Showing reviews 1-5 of 41 | Next

  1. Great fit and finish 5 Star Review

    Posted by on 26th Oct 2020

    Shoots great with minimal point of aim shift when it gets hot. It was not supposed to replace my xtc rifle but it shoots so well it may.

    Keep up the great work!

  2. FT. Benning replica A2 5 Star Review

    Posted by on 4th Sep 2020

    Got this build for a FT.Benning A-2/58 house of pain 1998, M16 A2 copy as close as I could make to my basic training rifle. I couldn't be happier.

  3. These barrels are amazing 5 Star Review

    Posted by on 24th Mar 2019

    I have now used 2 of these barrels, 1 on an M16A2 and the other on an M16A4 build. Excellent barrels, with great accuracy. The only improvement would be if GM added the .700" turned down area for the first 5/8" just behind the threaded area for the flash hider as are found on military barrels. But that's just me being nitpicky. I will use one on my next 20" barrel build.

  4. excellent barrel for heavier 5.56 ammo 5 Star Review

    Posted by on 4th Sep 2018

    Bought barrel for optimal accuracy for 69 & 77gr bullets. Exceptional accuracy great price.

  5. Very Very Accurate!!! 5 Star Review

    Posted by on 23rd Apr 2017

    No-brains accurate at a 25 yard zero of course. But once I let it go at long distances, this barrel amazingly accurate with my 75gr reloads (Hornady HPBT at 2800 fps)!!!

    I went shooting in a new area so I didn't have any distances measured. I was just shooting at random rocks, but kept note distinct formations of the mountains so I can reference the range on Google Earth. Once I did measured it at home, I was hitting up to 800 yards consistently!

    I bought this to get baseline readings for my M193 reloads and planned to upgrade to a 20" 223 Wylde in the future, but what for what?! It's already a laser!!!

Showing reviews 1-5 of 41 | Next