CMMG M2SG 10.3 Upper - Secondary Micro Gas Block

AR-15 » AR Discussions

AR Sponsor:

Site Notices

2024's Favorite CCW? | PSA Micro Dagger

[ARCHIVED THREAD] - CMMG M2SG 10.3 Upper - Secondary Micro Gas Block

Posted: 4/5/2006 3:00:53 PM EDT

What is the word on these uppers with a secondary micro gas block?

Do they run reliable?

Is it better than an LMT 10.5 with a Krink?

I am interested in semiauto operation only.

Posted: 4/5/2006 3:21:41 PM EDT

[#1]

interesting...

Posted: 4/5/2006 8:30:06 PM EDT

[#2]

bump

Posted: 4/5/2006 8:40:28 PM EDT

[#3]

Quoted:

CMMG M2SG(Short Gas) advanced 10.3 upper.

The M2SG has a secondary gas block mounted behind the standard front sight base. Gas is diverted earlier than on a standard 10" barrel through a small gas port. Gas is then directed up, rearward and forward. The goal was to increase the reliability envelope and decrease wear.

The M2SG uses a standard gas tube with a 2nd gas hole drilled. Gas that goes forward moves into an expansion chamber created by the excess CAR gas tube. The gas travels forward and is diverted through the FSB and stops at the barrel(there is no hole drilled under A2 FSB) This dereases the initial pressure spike normally associated with the carrier unlocking.

The carrier is unlocked with a push rather than a slap. This will reduce the accelerated wear associated with standard shorty uppers.

With the gas port farther back the from the muzzle the residual pressure is longer than with a standard gas system making for an all around more reliable system.

Additional specs: Barrels are .840 diameter, chrome lined, 1/7, 4150, MP tested and 5.56 chambered.

Here is a vid of some of the testing we have done. (40mb)
www.cmmginc.com/vids/Test_Vid.mpg

We ran two tests using one full mag of 77gr, one full mag of 45gr and one 20 rd mag with 10 different types of ammo ranging from 45-77gr.
www.cmmginc.com/vids/Test_VidII.mpg

Here is a photo of the ammo we used for the test. While the ammo ran differently all ammo all functioned without incident.

Check out the Vidoes

[ARCHIVED THREAD] - CMMG M2SG 10.3 Upper - Secondary Micro Gas Block

AR-15 » AR Discussions

AR Sponsor:

Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us