Polishing a rifle chanber

[Volpe]

How do I polish a rifle chamber thats alittle rough. Seems like its got one very small ding in it that makes the shell stick in the chamber after firing and the bolt wont open. It lifts fine just wont open w/out force. Noticed a very small mark on the brass and figure thats whats its gotta be...

 

[Big_R]

Polishing a chamber isn't something you want to do yourself. You could take it out of round, etc. Most of the time, a very small ding in the chamber won't cause difficulty in opening the bolt. I'm guessing you have other problems, over pressuer, excessive headspace, etc. What kind of rifle do you have, what caliber, and what type of ammo are you shooting?

Ryan

P.S. I know of a few rifle smiths who know what they're doing that actually rough up the chambers a little after cutting them. If they're too smooth, the brass will not be gripped by the chamber. That pushes all the force on to the locking lugs.

 

[Volpe]

The rifle is brand new (first time I shot it). I fired first with hornady factory 162 gr btsp with no probs. Then--I fried with Federal 160 gr nosler partitions as this is the load I intend to use. These are all factory loads. When I fired with the Federal ammo thats when the probs began. I checked the shells and the Feds looked like they were alittler hotter having a more flattened primer. Velocity for 5 shots was=2950/2963/2971/2976/2972. As you can see it was pretty consistant. When I was done I did my test--which is a golf ball at 200 yards and wammo--it disappeared. Each time the bolt got just alittle easier to open but I t noticed that the shells had a little horseshoe shape mark on them. The Hornady ammunition had the same mark but not as deep. Oh btw this is a 7mm rem mag.

Today-I took the gun and cleaned it. I scrubbed the chamber with Kroil and a 20 guage brush. Then I took it in the yard and fired it and the bolt opened right up with no probs. Dirty you say?? Nope--the mark was still there but nowhere as bad as it was and believe me I scrubbed the chamber. Now I have to take it to the range for another workout to make sure all is well as next year I'm taking this rifle to Africa.

As an aside--yesterday I also took my Marlin 1895 stoked with 405 gr. remington bullets and 3031 powder for an avg. vel. of 1820 fps. This gun shoots cloverleafs at 100 yards and also tosses around a 1 lb. coffee can at 200 if I did my part but man let my tell ya it was a pleasure to shoot the 7 mag after that....

 

[4 eyed six shooter]

I see not problem with lightly polishing the chamber. Take a wood dowel and put a thin cut in the end. Put a piece of 320 grit paper on it (about 1 1/2" wide) and wrap it around the dowel so that it fits into the chamber with a little slop. The idea is for the paper to fan out when spun by your drill, not be packed in tight. Put some kerosene on the paper and put the dowel and paper into the chamber. Spin at a medium speed for no more than one minute, 30- to 45 seconds should be fine. What you don't want to do is to get the paper into the sholder and throat area. Prior to placing the paper on the dowel, push the dowel into the chamber until the end contacts the edge of the shoulder. Then mark the dowel at the back of the receiver with a marker. When polishing, keep the dowel moving back and forth and do not push the dowel in past the mark you made. You will remove very little metal. The mark will not be removed from the chamber, but this should help to remove any raised metal. If you do as I described you will not enlarge or make the chamber out of round. You do want a little roughness as was mentioned in the prior reply. Hope this helps.
John K.

 

[Volpe]

Thanks 4 eyes that sounds like a plan. I'll keep that in mind if the prob persists. I wont know till I go to the range again and put it thru some paces. I used to be able to shoot all day off my portch but now I'm getting neighbors grrrrr. Time to move to Alaska--all I gotta do is convince the wife grrrr again .

 

[Jim K]

The dowel idea will work OK, as will the slotted end of a cleaning rod tip, but make sure if the tip is steel not to let it touch the chamber. I will, though, recommend 600 grit rather than 320. I think 320 is too coarse and could cause problems with brass that is on the soft side.

Jim

 

[Volpe]

Thanks Jim for another good idea. Sometimes in the quest for knowledge we overlook the simplest answeres...

 

[Riss]

Recall also a post from TFL, a chamber polishing mandrel made from a new case and coated with polishing grit. New case was secured to a dowel rod and spun by a drill. If I recall correctly the neck was also removed so the shoulder, throat areas would not be touched. Since case is same dimensions as chamber there was less chance of making any mistakes.