Injection issue AR-10 but only with reloaded ammunition

[Muleskinner]

I'm a little perplexed by this issue. I have a DPMS AR-10. It runs commercial ammunition with absolutely no issues. The rifle runs flawlessly and I can ring steel consistently at 500 yards. About 1 out of every three or four of my reloads get stuck in the chamber and I have to use the old mortar method to get the spent case out of the chamber. The odd thing is that they go into and come out of my case gauge completely with no problems and they chamber in the rifle with no problems if I take the upper off and plunk around in the chamber not only does it go in with no resistance if I turn it upside down it falls right out but after the gun is fired about 25% of them get stuck. The rounds themselves are very accurate they are not maximum pressure but the brass simply does not want to come out. If it was doing this with commercial ammunition I would say that I may have a worn extractor but commercial ammunition functions flawlessly. So, has anyone else ever seen this issue and if so what did you do to fix it?

 

[brianns]

Make sure you know how to read the situation in the case guage. In other words the, case head has to be within the upper and lower limits to ensure the shoulder is correctly resized(shoulder bumped back). Then you ensure its trimmed to the correct length before loading them up. I am the first to admit that when Iwas using the case guage I still for some reason did not catch the die was not set all the way down to fully bump the shoulder.

Also sometimes the cases rebound and don't 'take' the bump on initial resizing, especially in the military brass.

 

[brianns]

Here's a video on the case guage subject. I'm sorry it has an overly 'corny' intro. Also make sure the bullets aren't getting jammed or seated too deeply into the cases during cycling and causing over pressures.

 

[lazarus]

I'm a little perplexed by this issue. I have a DPMS AR-10. It runs commercial ammunition with absolutely no issues. The rifle runs flawlessly and I can ring steel consistently at 500 yards. About 1 out of every three or four of my reloads get stuck in the chamber and I have to use the old mortar method to get the spent case out of the chamber. The odd thing is that they go into and come out of my case gauge completely with no problems and they chamber in the rifle with no problems if I take the upper off and plunk around in the chamber not only does it go in with no resistance if I turn it upside down it falls right out but after the gun is fired about 25% of them get stuck. The rounds themselves are very accurate they are not maximum pressure but the brass simply does not want to come out. If it was doing this with commercial ammunition I would say that I may have a worn extractor but commercial ammunition functions flawlessly. So, has anyone else ever seen this issue and if so what did you do to fix it?

Are the cases getting stuck after fired? As in it isn't cycling and the case is stuck after firing? Or is this the gun fires, cycles a round and that next round if you try to manually extract it, it won't without mortaring?

 

[85MikeTPI]

I found that I have to use a small base die for my AR10 reloads, otherwise they stick in the chamber. Both 308win and 6.5cm

 

[alucard0822]

Often times AR10/AR308s have tight headspace, or 308 instead 7.62 NATO spec, and sometimes case gauges are more forgiving than the chamber. If they chamber OK by hand, see if it's easy to eject the round, and what marks are on the case, could be an extraction/ejection issue that can be other things, if it's double feeding you know it's slipping off, it if's not ejectintg or cycling at all could be a few other things. also as Brianns says you usually need a small base die as 308 semis beat the hell out of the brass, and the head can be out of spec. Brass matters too, have had NEW brass that I loaded that was too tight, 7.62 spec brass that was just a hair too long, presumably to tighten up accuracy in NATO chambers, but caused jams in my tight 308 spec BA and Faxon barreled AR308s

 

[John from MD]

I found that I have to use a small base die for my AR10 reloads, otherwise they stick in the chamber. Both 308win and 6.5cm

My experience too.

 

[lazarus]

Limited .308 reloading experience, but new federal brass has run perfectly in my .308 AR-10 so far. I haven’t reloaded it. I did resize the new brass before loading. Next time at the press will be used brass.

I am using standard Hornady dies.

 

[steves1911]

Is the rifle failing to extract or failing to chamber?

 

[erwos]

Getting stuck after firing sounds a lot like a trimming or pressure problem.

 

[GuitarmanNick]

If the brass is correctly sized and trimmed, I would look for a weak extractor and/or machine marks on the chamber walls that are holding onto expanded cases.

 

[erwos]

If the brass is correctly sized and trimmed, I would look for a weak extractor and/or machine marks on the chamber walls that are holding onto expanded cases.

FWIW, I had a gun that's doing like OP describes every round, and it was simply a bad gun. Ruger fixed it (and then some), and the problem went away.

 

[brianns]

Full length dies should be sufficient. Remember that the side wall of the case is not straight; its conical. So if you are slightly off in the shoulder bump, as in not far enough, the whole side wall will be slightly too wide in diameter all along its length accordingly. That can exacerbate the grip the case will have when it expands against the chamber wall. Somebody said above something about a less forgiving chamber(tighter, less headspace length as in a match spec). That means you have to tighten up your measurement of headspace to ensure you are not erring to the too much headspace.

 

[Jerry M]

As above: try small based dies.

 

[f1racecar]

Maybe you need to polish the chamber. Small chamber reaming ridges could be holding on to the brass.

 

[Triggerfinger]

I found that I have to use a small base die for my AR10 reloads, otherwise they stick in the chamber. Both 308win and 6.5cm

Adding to the choir, had the issue that was resolved with a small base die.

 

[Park ranger]

What is your load?

 

[lazarus]

Maybe you need to polish the chamber. Small chamber reaming ridges could be holding on to the brass.

Could also be it, and a higher pressure on a reload vs factory ammo could make that worse. Especially reloaded brass that isn't resized down as much. The more brass is used, the less elasticity it has, so it doesn't pop back as quickly or as much. That is why worked brass cracks/breaks eventually.

Not brass, but my Remington 870 had ejection issues from a very rough chamber from the factory. 000 steel wool on a drill bit took care of it. Ejects very, very smoothly now. I also had to police the chamber on something else. I think it was my 24" grendel upper. Worked fine with brass case, but wolf steel had ejection issues. Some steel wool polishing it and runs smoothly.