Over Gassed AR15 - What Does it Cause?

[lshel]

An over-gassed AR, I'm new to this term and AR's. I finished a build for a Spike's Tactical AR with 18" ss Barrel 1:8 twist in 223 Wylde. Recoil is very mild and accuracy when I do my part is less than 1 MOA at 100 yds. I do notice that brass is ejected around 1:30. Reading other postings, this is described as over-gassed if not ejecting brass 3:00-4:30. I have not noticed any excessive power residue or blowing powder residue or gas during recoil. I know from postings that an adjustable gas block is the solution. Will this condition cause excessive wear to BGC and upper receiver, if so is it after 1000's of rounds or 100's? Concerned.

[c.a.willard]

Over-gassing isn't the only thing that will alter ejection patterns.  Extractor spring being a little more stout than spec, or a off spec ejector and/or spring will cause the same ejection pattern.  If your experiencing mild recoil and good groups and everything is operating reliably i would say leave it as it is and don't worry about it.  

 

An over-gassed gun will cause premature wear, but your not likely to notice it until the round count gets way up there.  

[molonlabetn]

Are you using a lightened bolt carrier and/or buffer? That can exacerbate minor overgassing... Either way, an adjustable gas block is the way to go.

You are overheating and beating up your bolt... might crack at the cam pin hole eventually, is all. Would probably take thousands of rounds to actually break. Edited May 21, 2014 by molonlabetn

[Fourtyfive]

Two gas threads in the same evening ? Edited May 20, 2014 by Fourtyfive

[TnShooter83]

I'm not an expert and have not yet personally witnessed an "over gassed" rifle symptom.

But if one is "over gassed" usually it effect timing. The bolt will try to open to soon while the case still has pressure inside it.

When this happens the extractor can rip the rim of the case off. Look at your brass and see if the rime is damaged?

Yes, some marks will be seen where the extractor pulled the case from the chamber. This is normal. 

Bent or missing pieces of the rim are not normal.

If you are getting dented cases this could be from the cases slamming in to the case deflector.

Which could be another sign of an "over gassed" rifles.

 

Again this is my understanding what to much and too soon gas can do to an AR.

I researched a lot before I built my first AR. And I went with a Mid-length system on my 16" AR.

 

Now with all this said, There is a guy on here named Dolo_mite_Supafly.

He will be here shortly to clear things up and give you a better understanding of what to look for and how the AR works.

Or, you can PM. He is a great guy and is always willing to help.

[Ted S.]

Symtoms from personal experience:

* Harder kick
* 1:00 ejection pattern
* Damage to casings
* Gun runs a lot dirtier, noticable metal fragments in the gunk from casings.

Had a thread on this a few months ago, so for more info: http://www.tngunowners.com/forums/topic/73914-ar-15-possibly-overgassed/?view=getnewpost Edited May 21, 2014 by Ted S.

[Ehunt]

I am having the same experience with my new AR Pistol Build (8.5" Barrel, standard gas block), but don't want it to become an issue. The bolt missed locking to the rear two out of ten times (first and third shots, was most likely the weak 10 round Mag Spring); ejection is approximately 1:30-ish. I only fired a total of 20 rounds out of it today for a Break-In, but it seems to be okay otherwise. I was thinking of adding a stronger buffer spring (SprinCo's RED) and/or an H3 Buffer to calm down the 1:30 ejection, and save on premature wear.

[ReeferMac]

Try Simethicone!

[RED333]

29 minutes ago, ReeferMac said:

Try Simethicone!

Had to look that up

[walthermitty]

There is a lot about over gassing online.  A suppressor can cause over gassing.  There are adjustable gas blocks from Seekins, and an adj from Superlative that also has a bleed off system.  There are charging handles that cause gas deflection forward (away from the face) that also reduce over gassing issues and there are gas adjustable bolt carrier groups.  The effects of over gassing, like additional recoil, can be partially mitigated with a heavier buffer spring.  And, there are BCGs that withstand tougher usage, like from Sharps Rifle Company.

Or, Simethicone! (;>)

Edited November 11, 2018 by walthermitty