Chamburrrrrr!

antelopedundee

internet bum
So the other day I went to the range to test and settle on a load for an upcoming hunting trip. Rifle is chambered for .25-.284. Normally after I fire I collect the ejected case in my hand, but this time it hit the ground/concrete. After I retrieved it I checked to see if the case mouth was dented. It wasn't dented but I noticed 2 other things; a small split on the shoulder and a couple small scratches [the longest being about a quarter inch] from the shoulder juncture down towards the case head. So I chambered another round and extracted it to see if the scratches were still there. They weren't so that means that the scratches were only showing up when a fired case was extracted. I shot about 20 rounds and all fired cases had scratches. Went home and cleaned the gun. Did some fiddling and the scratches were still there after cleaning. I had some old fire formed Buzztail brass cases that were supposed to be 6.5-.284 necked down to .25. These would not chamber in the rifle, but when removed the case had the telltale scratches. Even when full length sized the cases still will not chamber in my rifle. I went back and checked some fired cases from the past and most had scratches so I figure that the burrs causing the scratches had been there for a long time or maybe even from the start.

So at this point since the gun shoots well I have just decided to live with the issue. Not worth the hassle IMO to send it back to the smith and have him fiddle with it since it's been more than 20 years since the gun was built. One thought I had was to take a brass .45 caliber brush, chuck it up into an electric drill and run that into the chamber to try to remove whatever is causing the burrs. Is that something that could be done without hurting the chamber?
 
Before using a brass brush to polish the chamber, I would use a cotton mop and some Ioso bore paste ( I take the threads off and chuck it up in a variable speed Dremel ) to polish it out. I have had good luck with this method on sizing dies.
 
Before using a brass brush to polish the chamber, I would use a cotton mop and some Ioso bore paste ( I take the threads off and chuck it up in a variable speed Dremel ) to polish it out. I have had good luck with this method on sizing dies.

I'm not sure what you mean by take the threads off.

Anyhow I wasn't planning on disassembling the gun. I would put it up in a vise with padded jaws, remove the bolt and put the brush or bore mop in a section of cleaning rod, put the rod into a drill and try and clean the chamber.
 
Take the threads off =. Use a small file to remove the threads from the bore mop and convert it to a smooth shaft so it will chuck up in the Dremel.

Spinning the mop in a section of cleaning rod would also get the job done.
 
Take the threads off =. Use a small file to remove the threads from the bore mop and convert it to a smooth shaft so it will chuck up in the Dremel.

Spinning the mop in a section of cleaning rod would also get the job done.

If I take the action out of the stock I'd still need something a foot long to reach the chamber, hence the cleaning rod section.
 
Are you quite sure the scratches aren't caused by ejection? Spring-loaded ejector setups will sometimes benefit from some tuning, I've got moleskin and tape on a couple of mine.
 
Are you quite sure the scratches aren't caused by ejection? Spring-loaded ejector setups will sometimes benefit from some tuning, I've got moleskin and tape on a couple of mine.

When I extracted and ejected a loaded round [which was made from new brass] there were no marks on the case.
 
Before using a brass brush to polish the chamber, I would use a cotton mop and some Ioso bore paste ( I take the threads off and chuck it up in a variable speed Dremel ) to polish it out. I have had good luck with this method on sizing dies.

Is Ioso anything like Simichrome polish or Gun Brite? Or is it a tad more abrasive? What's the best solvent to use to remove it from the chamber?
 
Well, yeahhhh, there wouldn't be. Because the bullet's in the way.

Do it with empties....

The rifle is a Rem 700 LH short action that has been nickel plated. So I resized a couple fired cases and chambered them. If I extract the case and hold it with my pinkie so that it pulls out straight there doesn't seem to be any added scratches on the case. If I extract it and let the end of the case contact the action on the way out then extra scratches appear so it may be that that is the root of the problem. I can't feel anything with my pinkie. Probably need to get a dental mirror and try to find the burr/s and use a jeweler's file to remove them. I've got several other 700s and have never seen that problem with them.
 
dental mirror, yes..... jeweler's files MIGHT get it done but I mis-doubt you kin' stroke it...... so a rotary tool IMO, and you'll need a perty long-reach dremel head. Don't bother with "polishing" yet, you've got some grinding to do first, my guess. I'll venture a 1/4 in or mebbeso 5/16 ball grinding burr
 
If you can clear a loaded round without scratching but not a bare case, then it seems to me that the scratch is coming from the mouth of the chamber or somewhere on the action rather than in the chamber itself.
 
If you can clear a loaded round without scratching but not a bare case, then it seems to me that the scratch is coming from the mouth of the chamber or somewhere on the action rather than in the chamber itself.

I can clear a case too if I hold it straight with my pinkie until it won't touch any part of the action during extraction. I don't have much for new brass anymore. I'll probably get together with Randy R and have him look around with his bore scope.
 
I can clear a case too if I hold it straight with my pinkie until it won't touch any part of the action during extraction. I don't have much for new brass anymore. I'll probably get together with Randy R and have him look around with his bore scope.

Bore scope is simply NOT the right tool..... just gonna' get grease on the mirror :) peer in there with a dental mirror. Or stick yer pinkie in and feel for burrs
 
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