Bore Lapping/Polishing for Firearms: Cheap Portable Solutions

[will0057]

Hi - sorry I'm not an engineer just desperate!

I want to remove pitting and marking in a shotgun bore and am having problems finding a tool which will do this in the firearms sector - and if I do I am sure it will be at a premium price - removing a small amount ie less than a thou of the internal diameter of a bore and polishing must be a fairly common requirement in engineering - does anyone know of a cheap portable tool which will do this (as opposed to factory honing) I want something I can put on a drill and spin in the bore - have tried brake honing stones but really need something which will apply equal pressure (or nearly) at all surfaces of the bore, the nearest I can get so far is to try rig up an expanding mandrel - is their anything commercially available?

Thanks
Will

 

[Danger]

I'm not sure whether or not this will work for you, but it might be worth checking out. There are valve-guide hones for auto mechanics. I don't know how large a bore they can service, though. Also, you'd definitely want to rent or borrow one; they cost upward of $350.
My only other suggestion would be to wrap sandpaper or drywall screen around a sponge on a stick.
(That's not my final answer, but I've got nothing else right now.)

 

[sophiecentaur]

Your bore is tapered, I imagine. That doesn't help.
How about a sponge mop and valve grinding paste? Lots of rotation and reciprocation to spread the wear and avoid high / low spots.