Mid-Length gas system in 223 function Question.

arlaunch

Active member
Howdy folks,

I have a new rifle build with a 16 inch barrel and a mid length gas system. Function seems to be 100% so far and the bolt locks back each and every time.

The oddity is that it coughs the brass out at the 1:00. Not much force at all on the ejection cycle.

When i first saw the low ejection force i was sure it would not even lock the bolt back at the end.

It does though.

I tried M855 ammo for the first 10 shots doing the single fire/clean routine. It does not seem to change with a change in ammo.

I have tried 2 different BCG's. Does the same thing...

Very strange indeed.

Next i think i will change the gas block. I have a spare on hand.

Any ideas fellas?

My other rifles either throw the brass out to the right and behind, or are tuned to do so.
 
based on the standard chart - it would appear you might be overgassed.

do you happen to have a bit heavier buffer (like a h2) you can throw in there to see if that helps?

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I wish it were that simple. The rifle functions very smooth, coupled with weak ejection. IMO it is not over-gassed at all.
 
What indicator are you using to determine it's over gassed? Does your ejector spring have adequate tension on the ejector?
 
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Originally Posted By: spotstalkshootWhat did the "low ejection force" look like?

It coughs the shell out prone and lands less than 2 feet away on concrete.

Locks the bolt back though... Just odd.

I took the extractor donut out of one of the BCG's. I will test it when i get a chance.

This very well could be way to strong of an extractor spring/donut combo. I have heard about the high power guys cutting their springs a tad and brass piles going more towards the rear.

Stay tuned.
 
My F-Class AR is set up with a weak ejector spring to only kick them just outside of the port. I would put a new spring in there and see if it clears it up. For $2.00 it's worth a try.

Greg
 
Unfortunately i have not had time to take that rifle to the range again lately. And won't know for some time as i have a huge household project in the works right now.

It dawned on me the other night that i had a Tubbs spring in the lower receiver. I am almost certain that is the problem. Too much extractor force and, way too much spring for that system.

To be continued.
 
Just my observations as a person who reloads, I think it has as much to do with the powder you are using as it does whether the rifle is over gassed. The Tubbs spring may have something to do with it but my bet is the M855 is propelled by a slower burning powder.(Winchester 760 or something similar) Just my view. If everything is working well the next big test is shooting in the dead of winter when the temperature is below freezing.

kwg
 
I shot it with AR-Comp and IMR XBR 8208.

Same exact symptoms.

Those two powders are significantly "less gassy" than most others i have tried.

I think it is the spring.

That spring works excellent on my suppressed rifles and my carbine gas rifles.
 
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