I have the Hornady annealing kit and I use it on sized cases as I don't want to heat the necks and then work harden them by running them through the sizer die.  Now if I'm going to form .300BLK from 5.56 brass then I'll anneal before sizing to reduce the chance of splitting the cases. 

What annealing does is relieve the stress of work hardening the necks from repeated sizing and helps with a consistent bullet pull during firing.  I'll anneal after about 4 reloads but it also depends on the brass so you really have to read what the brass is telling you and go from there.

Holy crap that's a machine right there!!!  I'm envious but I'm sure it wasn't cheap.  I'd love to upgrade to that but I'm afraid to know what kind of dent in the wallet it will make.

So I take it that the cases are dropping into a bucket of water?  Are you getting any scale or anything else that would cause you to tumble the brass?  That is a sweet setup right there but a little rich for my blood.

So I take it that the cases are dropping into a bucket of water?  Are you getting any scale or anything else that would cause you to tumble the brass?  That is a sweet setup right there but a little rich for my blood.

I just have it dropping into a bucket.  The brass cools off quite quickly that it's fine.  Most of my friends just drop into an ammo can or small cardboard box.  I have mine set so the neck gets to 750 degrees but does not exceed 400 degrees half way down the body.  I've got Tempilaq to check and currenty have it set for .308.

In terms of scale,  I've done it both ways.  Most of my brass was cleaned prior to annealing.  I had a bunch of brass that I annealed first, and then tumbled.  If I tumble after annealing, you can't really tell that it's been annealed.  If you anneal after tumbling, you can see a slight discoloration.

Here are some video's from others.

I have about 18000 rounds of 7.62 Nato in my garage.  Perhaps I should stop by!2

If you want to drop by, let me know.