AR 10 gas problem

[jesker]

I have a ar 10 in 308 win. I am trying to reload 130 gr bullets for practice shooting. I have tried multiple powders but pressure signs show up before reliable cycling happens. So far varget will cycle at 48.5 gr. But pressure signs are there. Does anyone know a powder that will give more gas without pressure signs.

 

[Coyotefurharvester]

Have you carefully verified your sizing die will result in brass that chambers AND extracts properly? If so(sizing properly is a big issue in gas guns) than a faster burning powder and/or buffer change maybe required to shoot bullets lighter than normal for the 308 in the AR10.

 

[marazzi59]

What's the barrel length, gas system length, port size, buffer weight, etc, etc? Is it DI or piston?

 

[MGYSGT]

Had that problem. Get the next size metric drill and open the gas hole in the barrel. If that doesn't work go one more.

 

[fatelvis]

Before drilling anything out, try some loads with a bit slower burning powder. A slower powder will continue to create gas as the bullet travels the bore.

 

[js2013]

Might want to try an adjustable gas block.

 

[marazzi59]

Drilling a gas port should not be your go-to, more like the last thing. That's usually treating a symptom not fixing the root cause

 

[10XSHOOTER]

Had a AR-10 in my shop a while back. That had a TIN coated Gold colored bolt. Fought it for a week and then figured out the Bolt was out of spec's, being to big of Diameter. Traded it out for a stock black bolt and it ran like a Timex watch!

 

[karrarararararar]

What exactly is the malfunction? AR10's are typically overgassed, not under. As asked earlier, what's your buffer/spring/gad length? My 260 would show pressure signs (case head swipes) early until I upped my buffer to H3 weight.

 

[Jeff Porter]

I have played with 16” .308, 20” .308 and a 24” .243 and all needed a heavy buffer and eventually went with adjustable gas block on all of them. All were over gassed even with soft loads.

You say it is not cycling which sounds under gassed. Is it ejecting the brass ? It may be running so fast the next round is not rising up fast enough to be caught by the BCG. Better mags may help but proper timing on the big AR is way harder than with a .223 version.

 

[jesker]

I think I have figured the problem out. The gun is not been broken in enough so I l
oiled it up good and it is working much better now. But thanks for your information

 

[Bill K]

Try some loads with CFE 223. You may find it will solve your problem. Start with the start load and work up.

 

[Loudenboomer]

You still may want to try an adjustable gas block. Much more flexibility in tailoring your loads.

Superlative Arms LLC.​

Has a good one. Very happy with mine. Great guys to deal with. They cut Veterans, LEO and First responders a break too.

 

[Konocti's Wigwam]

Also, something I don't see mentioned...check your buffer and make sure it matches what you need. I had a problem today with an 6.5 Creedmoor not feeding, but firing ok, so it wasn't cycling good. My first gas 308 was difficult to get working, and now I've taken enough parts off of it that it probably won't feed correctly either.

There's a lot of factors on gas guns, including the gas tube, gas block, buffer weight and magazines.

Wish I could be more specific, but every gas gun is a little different.

 

[ebb]

check and see if the gas block is properly aligned with the gas port hole in the barrel