Suppressed 308 gas gun malfunctions

[brutus1776]

I have a 308 rifle that I’m getting several stove pipes per mag, suppressed. Runs fine unsuppressed

Components:

Grey ghost upper/lower
Jp full mass bcg
Ranier 16” match barrel, intermediate gas ststem, .750
3.8 oz carbine aero buffer
Fed gmm ammo

I have a adjustable gas block on orfer

Looking for any advice on where to start diagnosing / fixing the issue. Particularly what buffer components I need to start looking at

Thanks!

 

[Zak Smith]

Use a JP SCS and turn the gas down until it works

 

[brutus1776]

Thanks, any rec’s as far as h2, etc?

 

[Zak Smith]

Regular SCS should be fine. Just turn the gas down.

 

[AMGtuned]

My ar10 didn't like the stupid little car buffer. Suppressed or not. Unsuppressed, it didn't like any handloads, and really only ran well with m80 ball . Ditched that shit, went rifle setup with a Magpul PRS, and it was one of the most fun rifles to shoot.

Or like Zak said, just go SCS and be done. A buffer system with more adjustment range will be beneficial in the grand scheme.

 

[brutus1776]

Thanks guys

 

[SoundFx]

What mags? I had a recent issue with pmags and one of my MWS’s. Runs fine unsuppressed with the pmags, chokes out suppressed. Swapped over to the Lancer mags and all was dandy.

 

[NightHunt]

If you haven't already, I would start with checking the gas port alignment between the barrel and gas block.

If that's good, then I second what others have commented as to an adjustable gas block and dial it in.

I wouldn't mess with the buffer or etc. unless the above fails to yield the desired result. Throwing everything at a problem at once doesn't help with determining root cause.

 

[r50140]

I went the other direction. Armalite basic factory 16” upper. 165 grain reloads, the rifle was over gassed, I ordered the heavy buffer from Slash at heavybuffers.com and never looked back. Rifle runs suppresed and unsurpressed without any adjustments. Have done the same with a AR15 chambered in 300BO. I have never seen the need for an adjustable gas block when running these heavy buffers. Your mileage may vary.

 

[Yondering]

If you haven't already, I would start with checking the gas port alignment between the barrel and gas block.

If that's good, then I second what others have commented as to an adjustable gas block and dial it in.

Before making suggestions, it's important to have a solid understanding of the troubleshooting process or what each thing does.

Your first suggestion would make sense if the rifle was undergassed. That's what poor gas block alignment causes.

The second suggestion makes sense to fix an overgassed rifle, which is correct in this case.

But there is never a case where both of those would be the issue. An adjustable gas block can't add more gas, only restrict it. If the rifle is in need of gas restriction, then the issue is not a misaligned gas block.


But yes, fix the gas first, then look at different buffer weights IF NECESSARY. Most likely it will not be necessary. Don't screw around changing multiple things at once, and metering the gas correctly is the #1 thing these rifles require.

 

[NightHunt]

Before making suggestions, it's important to have a solid understanding of the troubleshooting process or what each thing does.

Your first suggestion would make sense if the rifle was undergassed. That's what poor gas block alignment causes.

The second suggestion makes sense to fix an overgassed rifle, which is correct in this case.

But there is never a case where both of those would be the issue. An adjustable gas block can't add more gas, only restrict it. If the rifle is in need of gas restriction, then the issue is not a misaligned gas block.


But yes, fix the gas first, then look at different buffer weights IF NECESSARY. Most likely it will not be necessary. Don't screw around changing multiple things at once, and metering the gas correctly is the #1 thing these rifles require.

I agree with a majority of your statement and whole heartedly with what an adjustable gas block does.

However a few years ago a friend was having the same issue that the OP posted. Rifle appeared to operate fine until he was running his can. To the best of my recollection it was a mid length system on a 16-18 barrel. The first thing told him to do was order an adjustable gas block. When we went to install it I noticed the gas block had a slight cant to and was riding against the barrel shoulder. I realigned it he ran a few mags through it without an issue and still does to this day.

 

[Yondering]

I agree with a majority of your statement and whole heartedly with what an adjustable gas block does.

However a few years ago a friend was having the same issue that the OP posted. Rifle appeared to operate fine until he was running his can. To the best of my recollection it was a mid length system on a 16-18 barrel. The first thing told him to do was order an adjustable gas block. When we went to install it I noticed the gas block had a slight cant to and was riding against the barrel shoulder. I realigned it he ran a few mags through it without an issue and still does to this day.

Then your friend's problem wasn't an overgassed rifle. It may not even have been a problem with the gas block itself, but with gas tube alignment at the bolt carrier.
Per your description he ordered an adjustable gas block but did not install it - so what does that have to do with anything?

Sometimes it's difficult to follow the logic of people who throw out these random anecdotes that don't actually prove their point.

 

[NightHunt]

Then your friend's problem wasn't an overgassed rifle. It may not even have been a problem with the gas block itself, but with gas tube alignment at the bolt carrier.
Per your description he ordered an adjustable gas block but did not install it - so what does that have to do with anything?

Sometimes it's difficult to follow the logic of people who throw out these random anecdotes that don't actually prove their point.

Logic: the symptoms of the unknown failure mode were the same as the OP's.

The original gas block became suspect as it was visually not where it was supposed to be.

The first action was to correct what may have been causal.

Realigning the original gas block solved the issue.

The non reoccourence of the issue was proof of effectiveness.