View Full Version : Not your typical failure to extract
1moregunaddict
11-12-12, 19:43
I dont want to send my upper to rock river if i dont have to, but about 1 out of every 20 rounds will fail to extract, and become stuck in the chamber. When i tap the fired brass out from the muzzle end, there is a piece of the rim ripped off from the extractor. I am taking it to my gunsmith tomorrow to check the headspace, he said he had seen similar problems from 6.5 grendel barrels that needed the gas ports opened up, to me it seems like the chamber is to tight, causing excessive pressure required to remove the brass, but i could possibly understand the port solution if opening the port slows down the timing allowing the brass to contract slightly and come out easier. The gun is a rock river lar8 with a vltor stock kit, and a daniel defense handgaurd. It has roughly 500 to 700 rounds total through it, and the problems seem to only happen with military ammo, m80 ball, first w/ some old surplus i picked up at a show, and now with some new stuff. It has never happened with winchester 308 hunting stuff, even when reloaded. I will try to get pics up in a day or two. Any help is appreciated, thanks and happy veterans day to all who have and are serving.
1moregunaddict
11-12-12, 20:37
trying to post pic...
1moregunaddict
11-12-12, 20:40
pic attached
I'm no expert but I actually stayed at a holiday inn express last night,
I suspect you have a 223 chamber.
I'm no expert but I actually stayed at a holiday inn express last night,
I suspect you have a 223 chamber.
Sorry my mistake it appears you have a308 chamber instead of a 7.62 NATO chamber
Opening the gas port will actually cause more gas to flow and won't solve your problem as far as I know. I suspect an issue with the chamber.
Failure2Stop
11-12-12, 22:56
Opening the gas port will actually cause more gas to flow and won't solve your problem as far as I know. I suspect an issue with the chamber.
This.
Also might want to check your extractor and springs, as well as your action spring.
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I dont want to send my upper to rock river if i dont have to, but about 1 out of every 20 rounds will fail to extract, and become stuck in the chamber. When i tap the fired brass out from the muzzle end, there is a piece of the rim ripped off from the extractor. I am taking it to my gunsmith tomorrow to check the headspace, he said he had seen similar problems from 6.5 grendel barrels that needed the gas ports opened up, to me it seems like the chamber is to tight, causing excessive pressure required to remove the brass, but i could possibly understand the port solution if opening the port slows down the timing allowing the brass to contract slightly and come out easier. The gun is a rock river lar8 with a vltor stock kit, and a daniel defense handgaurd. It has roughly 500 to 700 rounds total through it, and the problems seem to only happen with military ammo, m80 ball, first w/ some old surplus i picked up at a show, and now with some new stuff. It has never happened with winchester 308 hunting stuff, even when reloaded. I will try to get pics up in a day or two. Any help is appreciated, thanks and happy veterans day to all who have and are serving.
It sounds way over-gassed.
sinlessorrow
11-12-12, 23:38
Opening the gas port will actually cause more gas to flow and won't solve your problem as far as I know. I suspect an issue with the chamber.
probably this
1moregunaddict
11-13-12, 06:51
I dont think i explained it clearly to my gunsmith when he thought it was an under gas issue. I know stamped numbers dont mean anything, but the barrel is marked 7.62x51, and the manual says you can shoot anything under 2700fps. The extractor is working fine and i do remove it to clean behind it after each range session. If you look close enough at the pic, you can see that part of the rim is missing from the extractor doing its job. Thanks for the replies, keep them coming.
As others have stated above, it's probably a chamber issue.
Heavier buffer or spring to slow the timing allowing pressure to drop?
Not a pro, just throwing an idea:)
1moregunaddict
11-13-12, 11:04
I thought that too, but it seems like a band aid for the real problem, i'll keep you posted.
it really sounds like a bad chamber, way too tight, the extractor is working well because of the piece taken off the case, if it were me I would find a go, no go gauge and check the chamber, I would say find a reamer but they r kind of expensive if you dont have multiple projects that a reamer is needed. You could try and polish the chamber, that might help.
If you can get ahold of a gauge, id check it, and if out of spec, send it back. You dont want to pay for something they messed up. If you buy a new car and it keeps stalling out - do you fix it yourself or take it back to the dealership? ;)
Gool Luck and hope it works out for you.
if it were me I would send it back before pay for a reamer if the chamber is out of spec, that would be my advice.
I agree send it back, hopefully they will remedy the issue.
The_Hammer_Man
11-16-12, 05:33
I've seen this before on the RRA 308s that come through the shop.
Check your chamber dimensions. It sounds like it's too tight and when it warms up it seizes.
If it's a stainless barrel or isn't chrome lined reaming the chamber won't be too cost prohibitive. If it is chromed.. send it back and demand a properly reamed one. (Reaming chromed chambers sucks balls)
patrick sweeney
11-16-12, 12:39
Definitely slap the power drill out of the hands of anyone who says it is under-gassed.
Most likely, a tight chamber, or a short throat/leade. First step, send it back, with a fired case.
If it comes back and still does this, then it is time for delicate measuring as to chamber size and throat length.
The barrel markings, in many instances, do not mean anything.
restfortheweary
11-17-12, 09:30
My Le901 did the same thing with M80 ball this week. It was magtech and had the green sealant around the primer. Is that what Ammo you are shooting?
Heavy Metal
11-17-12, 10:16
Try different ammo before you do anything drastic.
1moregunaddict
11-17-12, 18:39
Ill get more pics up later, but here is the update: i took it to my gunsmith on tuesday, we took the barrel off and it looked like there was some kind of varnish or crud of some sort about three fourths of an inch from the rim. In the same spot on the case there was a dark ring, so we put a finish reamer in the chamber and just turned it by hand with some lube until the stuff was gone, then cleaned the chamber thoroughly. The idea is that the thousandth or two that the "crud" is taking up was causing the case to form around it,(think hourglass shape) and thus lodging it in the chamber. I got to take it to the range today and rapid fired 20 rounds, then fired another 20 rounds about one shot every 10 seconds without any issues. I will get out there again tomorrow test further and let you know. I dont have anymore of the old bulk stuff I was using when this started, but I'm thinking it had some sort of coating on it. Also I am currently using magtech ammo, so maybe there is more to that side of it. I will try to get more pics up soon, and will update after tomorrows range session. I talked to rra about this awhile back, and their tech said it would be months before he could get around to it, hence the desire to take care of it myself or locally if possible. Thanks again for the replies.
1moregunaddict
11-17-12, 19:05
here is pic
1moregunaddict
11-18-12, 14:34
Put 50 more rounds down the pipe today without a hiccup.
Let us know if it happens again.
I would be concerned about how the crud got in there in the first place so as to not get it in there again. Maybe it can from the surplus ammo you used?
1moregunaddict
11-20-12, 18:36
Thats what im thinking
Suwannee Tim
11-20-12, 18:42
......Check your chamber dimensions. It sounds like it's too tight and when it warms up it seizes......
When the barrel warms up the chamber gets bigger not smaller.
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