I certainly need to read your thoughts on this...
I was going over some of my reloading steps with a riflesmith I trust and admire very much. One thing I never knew or heard of is what he wrote in an email to me recently about the use of tumblers/vibrator-tumblers and brass cleaning...and what they'll do to a hand lapped barrel. Anyone ever hear of this?
<font color="blue"> ..."Throw that tumbler in the dumpster. If you got to have super shiney brass, clean and hand shine the outside of the case. I just hand clean the powder residue from the outside of the neck with a paper towel wet with a little SuperTech Carb. cleaner I get at WallyWorld. The sooner the better after fireing the case. Tumbling media is abrasive...some tumbling media has extra abrasive added to it. Why would you want to contaminate the bore of a premium match grade barrel with abrasive and fire bullet after bullet over that abrasive and each round you fire you keep adding more abrasive to the system and keep fire lapping the bore??? I know you hear alot about fire lapping out there from complete idiots...including some very famous ones. Here is a guarantee from a premium match grade barrelmaker --- want to ruin a PMG barrel, fire lap it."
After I responded with disbelief, he wrote:
<font color="blue"> "Makes you want to puke to hear about some of these little custom bullet makers that pour a bunch of polishing compound on top of their corn cob media to put a mirror finish on their handmade bullets. Yea buddy, that's smart...let's see if we can embed enough corundum into the soft copper metal jacket to make it a ceramic bullet. And then they bitch about why their barrel never stops copper fouling."
Here was his advice on annealing:
<font color="blue">"I bet if you Google "How to anneal rifle brass" you will find out more than you ever wanted to know about the subject...search the archives of the 1000yd. forum on Benchrest.com. I spin mine at about 60 rpm on a little variable speed motor so the necks heat up evenly then quench them in a 5 gal. bucket of cold water...and yes, I do have to wear welding gloves. Warning -- don't heat too long and let the heat get down into the body of the case...that's why they call it "neck annealing". Depending on how your propane torch is adjusted, it only takes a second or two.
I have a LOT of respect for this guy. He built an amazing rifle for me. He also makes his own dies, bullets, etc. But I have never heard of not using a tumbler (well, mine is the vibrating kind). But I called a couple other guys I know from the range and another bullet maker, and none of them use tumblers either. They all use lacquer thinner and acetone.