I have a vibrating tumbler that I plan to use to clean brass. I have some corn cob media to use in it. How long should I run the tumbler to ensure the brass is good to go? I will be cleaning handgun rounds mainly. 9mm/.38 Special/357 Mag/.45 ACP
No experience here with a vibrating tumbler, but my rotating drum with plain corn cob media (Lizard bedding from the store) takes a couple of hours to be up to my standard of "clean".
Every so often, I get a wild hair to drop in some Brite Bore to the mix. Cuts down on the dust, and helps take off the soot. Makes a mess to clean out the tumbler though
I only run mine about :30 minutes, but I've seen guys run theirs for hours. I really don't need that much time, as I pick up my brass before it gets too dirty; clean it and put it back in the reloading rotation.
If I find a load at the range, I will clean it for about :45 minutes, depending on how dirty it is.
Depends how dirty the brass is and whether you want it clean or clean and polished. To clean with cob I usually turn it on and go do something else for two or three hours. Mostly because that's about how long it takes me to remember I turned it on in the first place. When I polish, I prefer walnut shell and some liquid polish (after I already cleaned it first). Same two or three hours. You know what they say about opinions and *******s though. Trial and error will be your best friends. You can't clean it too long. I'm guessing the tumbler would burn out first.
Combine posts 3 and 4...you've got the perfect answer. With brass that was just shot, 30 minutes is plenty. If you want SHINY brass, not just CLEAN, then CQB's post was spot-on (with a vibratory case cleaner). Some guys will go all out with wet stainless steel pins to get their cases free of every little spec of dirt, inside n' out. If you're just reloading ammo and don't plan to set it on the mantle, the two posts above are all you need to know.
The guys above pretty much nailed it. The only thing I can think to add is that the brass will tell you. As the media gets older/dirtier, it takes longer to polish the brass if shiny brass is what you want.
I have a two stage process. First for 45 minutes is a coarse, treated media. Brass comes out clean but dull. Second is 30 minutes with untreated fine corncob media. Brass comes out very shiny.
I like this stuff as well. If I am just cleaning handgun cases to plink with they just go in the vibratory tumbler. When I clean rifle cases they go into the tumbler to knock of the grime then get sized and deprimed, and then through a cycle in my ultrasonic cleaner.
Re-use, it won't last as long as untreated though. I add a few recharging drops of polish every 500-750 cases. It's still trial and error though. Lots of factors in play. How dirty were the case to start with, how old was the media, how much media is in the tumbler, how many cases are in the tumbler at once, how well the tumbler you have works (like women, they all can shake it, but some do it better), but most importantly, your level of beer goggles when you check the brass to see if its done. I can say that there is very little you can do that will damage the brass under normal tumbling medias. You will get a system down that works for you. If you're not a waiting kind of guy you'll find a minimum needed approach or if time's not a factor you can hand polish every case and give them names and back-stories in preparation for that giant buck they'll get you. There is no wrong way if you like the outcome. It's all fun.