Another question for you folks...so I tumbled my first batch for almost 4 hours with the walnut and capful of NuFinish. Brass on the outside looks shiny but the inside is not. Do I tumble it some more or is walnut media not going to get the job done for the inside?
I use a Lyman Turbo 1200. I prefer corncob if I'm buying pre-made stuff, so I don't have to deal with the god awful red power that seemed to coat the inside of the casings when I made the mistake of buying walnut the first time. Maybe it was just crappy media, who knows. With the corn cob you just wipe off a little bit of chaff when you're done and on to the next batch of casings. I got a couple of jugs of Lyman media on sale and have been using it forever, so I haven't looked in to alternative media as mentioned above.
You might find that you have a little chunk of media in the flash hole that doesn't want to come out when your done tumbling, but that will go bye-bye when you de-prime your brass.
I use 2 or 3 caps of NuFinish, but my tumbler holds a lot of media. Pour it in while the tumbler is vibrating, stir it a bit to help it coat the media and prevent it from lumping up at the bottom, leave it running for a half hour and you should never have to worry about it again while you're using that batch of media.
The casings should be left in for 2-3 hours if you want them to really shine. I just leave mine in for 3 hours and they come out spotless every time.
Seems obvious, but if 30 cal brass goes in with your 40 or 45 or your 40 goes in with your 45, invariably a bunch of the smaller casings will get lodged inside the larger ones and the insides of the larger casings won't get scoured. So keeping a close eye on that will help as well.
To address your question though, the outside of the casings will get nice and shiny and the inside will get scoured out just enough to get it clean but it will not be shiny. This does not matter in the slightest, however, since the interior of the case does not need to be shiny, but should just be free of unburned powder, residue, debris, etc. Ditto for the primer pockets.
If for some reason you need the inside of the case and the primer pocket to be shiny as well(I dunno, maybe you're selling the casings and want them to look as new as possible??), you will have to de-prime your brass first and move to a wet tumbling system with stainless media and some sort of detergent solution. Frankford Arsenal makes a really good wet tumbler. I've tried it and it worked really well, but found the process to be a gigantic PITA, and went back to the Lyman after a few batches of brass since it does just as good a job for all intents and purposes.
