Good thread. Some ammo, and some batches of some ammo types, will not work well in a given pistol. Worth doing a plunk test with any given type of ammo to make sure it seats well and extracts easily in your pistol. Chamber specs, irregularities, powder residue, etc., can cause dimensions to vary. The chamber in a given gun may also be a bit oversized or undersized, scratched or scuffed up, etc.
Some serious shooters will test every self-defense round they intend to carry with a plunk test - to make sure there are no surprises.
Chambers can be cleaned like the barrel - with a solvent and brass wire brush - but also can be cleaned with Flitz. But I avoid using any mechanical (motor driven) buffing wheels inside the chamber -- because I don't want to make a dimensional change in the metal. Given mechanical driving power, speed in RPMs, resultant heat, etc., you probably could damage the inside of a barrel or a chamber even with Flitz, which the maker claims has no abrasives. Flitz, which does miraculous work in polishing my stainless steel watch, should be avoided on blued parts of guns.
I've hand-loaded a lot and shot most of the common brands -- including a bunch of Herters that was actually S&B -- and lately have been shooting MagTech and S&B 115 grain because it is available at good prices (around .25 per round) on the web. Most is well within spec but occasionally a couple of bad rounds will sneak through (I have seen two or three rounds out of thousands with primers in sideways or backwards). FWIW, I've never had any problems with WWB, which gets maligned a lot on the interweb. I stay away from Russian-made ammo, whether in brass cases or mild steel cases.
