Ok, so here is the deal with the latest enfield (MK IV):

If you look in the chamber you can see what looks like a little burr, almost as if someone stuck something in there and gouged it somehow.  Cartridges feed fine, but after they have been shot, they tend to 'fireform' around this and are almost impossible to remove.  Once removed you can see a little dent in each case where the chunk is.  

Anybody have any ideas on the best way to smooth this out?  I thought about a finish reamer, except for the fact it would cost more than the gun.

Thanks for any help you can provide.

Dan

Not sure a finish reamer would do it anyway.  SMLE’s have a reputation of oversize chambers so a commercial finish reamer might not be large enough to clean things up.

Obviously you don’t want to in any way enlarge the chamber itself.

First thing I’d try would be to simply (but very carefully) cut the burr down with a Swiss needle file.  Granted getting at things and seeing what you’re doing might be difficult.

Or maybe get a long, round file like a chainsaw file with as fine a cut as possible - grind it down and/or tape it up so only a small bit of the cut is exposed.  Then use that small bit of cut to cut the burr down.

Alternatively, maybe get an empty .303 case, attach the rear of it to a rod, glue a small piece of wet-and-dry paper to the side of the case in the proper location, and feed the case into the chamber and work the paper back and forth over the burr.  You might actually be able to much the same using an abrasive rather than the paper, though I’d be worried about enlarging the chamber.

That’s all I can think of.

I polished a rough chamber on an old 91/30 using a large hunk of T-shirt gobbed with automotive type rubbing compound, stuck in a large caliber patchholder, which was screwed onto the end section of an old multi-part cleaning rod chucked in a drill. I just spun it till the chamber shined up a bit. You just have to be sure not to push the whole thing in so far that you contact barrel rifling. If your gouge is small enough, this may be enough to knock it down. just another idea. Good luck.

I've run into this, myself.

I used a needle file to knock the "high" spots off of the burr, then I used a jag wrapped with canvas, that I then applied jeweler's rouge to, and chucked the rod up in a cordless drill.

Took a while, but worked great and really smoothed out the chamber.