Molly over at castboolits posted this re: bore polishing"
"I stumbled across another neat little trick that may interest the PP crowd. It's a take-off from something I wrote up for the CBA a while back, but here's the whole story:
Some time back I bought one of the unfired Yugo 8x57 Mausers because they were such bargains. But when I got the cosmoline off of it, the bore was pretty rough. Not rusted, not pitted, but it looked like it had been finished with sandpaper.
I didn't want to throw it away, and at the same time, I didn't want to pour coarse abrasives down a new barrel as was recomended for conventional firelapping. I decided to try something a bit less radical, and used JB Compound on a bore mop the coat the bore of the rifle. Then I fired a light jacketed bullet load, used the mop again, fired another light load, etc. When I was done, the bore looked like a mirror, and without any noticable enlargement. I wrote it up, and several people have tried it with excellent results.
A recent discussion of various grades of paper for PPing and various PP lubes brought the experience back to mind, because I wondered if anyone appreciated the fact that TiO2 - added to make paper whiter - is also a very, very fine abrasive. You can get the idea if you just walk over to the wall of your room and rub it with a nickle. It'll generally look like you wrote on it with a pencil, becaue of the metal polished off by the TiO2 (& other pigments). I'm a retired paint chemist, and I knew about this, but just didn't make the connection before.
Anyhow, my first thought was to wonder if anyone had noticed any polishing effect from ordinary PP lead bullets. Then I put two and two together, and wondered what would happen if I 'lubricated' PP cast bullets with JB compound! Just finger rub it into the PP after wrapping, drying and sizing. Works great, and without all the trouble of the bore mop approach.
I wasn't trying to develop a more accurate load, and didn't test for accuracy (I shold have, but didn't.) I was trying to test another approach for polishing bores, and I got that in spades. FYI, I used a moderate load with wheelweight alloy in a 30-06. Nothing fancy, but it worked fast, easily and well.
So if you've got a rifle (or pistol for that matter) that's prone to fouling or leading, you might want to give this a try. If you happen to have a bore that has been rusted, it MAY be possible to salvage it like this, using an appropriate grade of very fine abrasive polish. I'd recommend that you steer well clear of the coarser abrasives often recomended for fire lapping. For some reason, the very fine abrasives like JB compound seem quite effective here, and polished the bore of the Yugo M48 in about 5 or 6 shots. I see no advantage to coarser abrasives, and I can see numerous potential problems they could cause.
Of course, the usual caveats apply: These results were obtained using components, equipment and techniques that will differ from yours, so approach this experimental procedure with great caution if you decide to evaluate it yourself. NEVER use experimental procedures of this nature - or any nature - with maximum loads unless you work up very gradually because the interactive effects could produce dangerous pressure levels. Since you are the only person controling most of the variables involved, you will have to accept full responsibility for the results of your judgement and practices.
Regards,
Molly"
