A little perplexed

wvbearhunter · Oct 18, 2024

I am currently running a 20" Wilson Super Sniper in 308 Win lately. It been amazing and is absurdly accurate. I also shoot a Seekins PWS MK218 which is another excellent rifle. Something I have noticed with both as I develop loads for them:

Even factory 147 gr FMJ tend to have substantial ejector swipes and flattened primers. I was running Aguila today and all the casing are non-reloadable due to ejector peel marks, from both rifles. I tried some handloads I was working up for a bolt gun, a minimum charge of Varget, same thing.

Is this a common issue with AR10s? I will admit I do not shoot mine often, its usually a 300blk or one of my bolt action rifles. It seems a waste of good brass.

Both rifles are running Adj gas blocks and A2 rifle length buffers

Bucklowery · Oct 18, 2024

Sounds like over gassed. Where is it throwing your brass?

Thanks

Buck

wvbearhunter · Oct 19, 2024

4 o'clock. Seems odd both riffles would be doing it. I planned to dial back the adjustments today to find single feed and see how it shakes out

Tiny Tim · Oct 19, 2024

Agree with @Bucklowery, sounds over gassed. Does seem odd that what I assume to be "factory" rifles having the same issue.

Brathany · Oct 19, 2024

The rifle might not be over gassed, but the buffer spring might need to be heavier. A 4 O'clock ejection is typically a good thing. I have corrected many AR10 platforms from ejector swiping by manipulating the springs and buffers. The problem is the current system isn't allowing the case to stay in the chamber long enough after firing and the brass is still at the hottest point allowing the ejector to swipe. Check out SpringCo springs.

joelpend · Oct 19, 2024

I have never been able to run the same loads in gas guns that I run in bolt guns. Usually a grain or two less powder. I have seen factory loads that were just too hot for gas guns. That said using heavy bolts, heavier springs and buffers, turning gas down until the bolt just locks back on last round fired may fix your issues. AR-10s are hard on brass at best. I have seen them rip a chunk of the case rim right off.

LRhunter514 · Oct 19, 2024

I have not had much success with Aguila brass, I would try different brass

wvbearhunter · Oct 19, 2024

Made some progress today. I reduced my gas settings down to #1 (first full power setting).
First pic is the same handload from yesterday
Second pic is using Acc 2460 instead of Varget

Velocity were 2686 (5 shot avg) and 2665 (5 shot avg)

I ordered a heavier buffer from KAK and a flat spring from Tubbs so we will see if I can beef up the loads later

Brathany · Oct 19, 2024

Federal brass is also softer in the case head. Been a known fact for many years. There are more brands with softer heads than not. Remington, Lake City, Peterson, Alpha, are hardy.

Citified · Oct 19, 2024

I have run into this on a 308 AR I built. The dwell time of the case in the chamber is the problem. A heavier buffer spring or weight will cure the problem but you may need to increase the gas flow just a bit. You are on the right tract with the parts you ordered. If the case dwell time is too short the case rim can almost be torn off.

A little perplexed

wvbearhunter

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Bucklowery

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wvbearhunter

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Tiny Tim

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Brathany

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joelpend

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LRhunter514

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wvbearhunter

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Brathany

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Citified

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