pre-treated fire lapping pistol bullets

[Gtek]

The few that I have done, the cylinders were pinned and I was happy, forcing cone close enough. So, I took a small artist brush and cut it off and placed the mixture in a VERY, VERY thin coating in forward cone area and I used range scrap on full wad cutters tumble lubed and @ 700ish. Years back chasing thread choke I went the other way with same application. Brushed grit from rear just past choke/frame area and pounded through pure slugs from front on through. Very slow and tedious but can get you where you want if patient. My fear has always been on doing this with loaded rounds in revolvers is possible damage to throats. But if they were found undersized now I think I would blast away monitoring throat and then send Mr. Doug a cylinder to make perfect for application if it worked out that way.

[Bigslug]

I've done a number at this point to remove frame crush from the rear of the barrels. As others have said, you want enough powder to reliably get the bullets pooping out the muzzle, but not a great deal more. If they're hitting the ground less that 25 yards in front of you, you're on the right track. Make sure you see a downrange impact EVERY time, and have a brass rod and mallet handy for when you get one that sticks.

Going in, one other thing to check is if you have uniform diameter of your cylinder throats. In cases where some are tighter, I shoot my fire-lappers ONLY out of those chambers.

It's also worth taking your cleaning equipment and pin gauges to the range with you so you can verify that the frame crush is gone from your bore and your chambers have reached uniformity. If you don't have a set of pin gauges, get one (MSC). In this game of bullet casting, you'll find it pays its way VERY quickly.

[fecmech]

I had a rough throat in a 94 Winchester .357. I put automotive rubbing compound in the lube grooves (instead of lube) of some wadcutters and shot them. Cleaned the throat up nicely.

[lx2008]

dont want to beat this thread to death but i found an article in an old handloader magazine of mine about lapping bbls.
i was about a fellow who hand lapped his bbl. using a fire lapping kit only instead of embedding the series of finer grit compounds
in boolits, he use a lot of cotton bore mops in with each finer compound. anyone ever hand lapped this way? basically just "scrubing" the bbl with each compound.

[crash87]

I use the LBT method, have done on quite a few revolvers. Mostly to get rid of thread choke, but also smooths out rough spots where roll engraving was used on the barrel. Fermin explains it very well here.....
https://gunblast.com/FerminGarza-Firelapping.htm