tkcomer,
you're answers in context below:
"'I'm thinking about giving up my Rockchucker and going to the Lee Classic Turret press."
Hang onto the Rock Chucker, you'll still find useful things for it to do and it's paid for. I sold mine, got a Lee Classic Cast single stage, now son's got that and I wish I'd kept the RC to give to him.
"Calibers I'll be loading are 38, 357, 44 mag, 223, 243, and 308. Now then, I'm kinda confused on the Pro Auto Disc."
A list of everything you could possibly need to load anything on a Lee Pro Auto Disk when using it on a Classic Turret press:
1. Pro Auto Disk
2. Double Disk Kit
3. Micrometer Adjustable Charge Bar
4. Micro Disk
5. Auto Disk Riser
6. Rifle Charging Die
Note: This seems like a lot of stuff, but most items aren't a 6-10 bucks each (wholesale to retail) tops each. So you can pick up the whole kit and kaboodle for not a lot invested.
What do I need to buy to set the powder measure up to load for the rifle cases?
For Rifle at a minimum:
1. Pro Auto Disk
2. Double Disk Kit
3. Auto Disk Riser
4. Rifle Charging die
Note: By the time you buy this stuff, you might as well get the extras above.
"I see a rifle charge case in the Midway book, but the Lee site says it's a small capacity rifle die."
It will handle up to a .308 case according to Lee's documentation. I have one set up for .303 and it works fine for that as well.
" I know I need the double disc kit and possibly the micro disc conversion unit. Does the micro disc work in conjunction with the regular disc?"
I don't know yet, but plan on finding out. I recommend you buy the list above, it's so affordable, it's worth it to do so.
"I'm trying to figure out what I'll need to set this thing up without having to realize that oh, I need a $10 part with $8 shipping to get it running. And then find our I need a $15 part to do what I want after the $10 part comes in."
Smart thinking, this is the exact reason I'm advising buyig the complete first list above. Then you have everything for any setup and there's nothing left to buy. I bought everything but the micro disk and I wish I had bought it as well.
"I'll have to get new pistol dies for sure as mine are old and they're not carbide."
After just buying several sets of the Lee Deluxe 4-die pistol sets, I highly recommend them. I like the dies better than most other dies I have and I currently own Hornady, RCBS and have owned Dillon in the past. They are easy to adjust and do a good job. The only thing I don't like about them is the o-ring instead of the set screw for the locking ring, but I've learned how to deal with that now or if you get tired of it, change to a Hornady locking ring, which I do for the powder measure die.
"I think I can still use my rifle dies, but will add a factory crimp die to the 223 as I shoot it in autos."
If you're going to buy one Lee die, might as well buy the deluxe set. Then you have extra dies (can be handy with two presses, especially if one's a RC with a Lock N Load bushing adapter setup in it) and the collet dies are great for bolt actions. My plan is to get and use low usage dies on a new Lee Classic Cast single stage (special purpose) I'm getting and keep the more standard dies on either my Hornady LnL (high volume) or my Lee Classic Turret press (medium volume)
"The other two are neck tension only."
I suspect you'd really like those Lee collet dies once you got used to them.
As a interesting side note, I have an RCBS measure like yours as well. RCBS will replace that worn out part for free if you call and ask them on their 800 line. Also, I plan on adding my RCBS to my older LnL CAPD and trying it out on the Lee Classic Cast turret to see if it has enough riser to clear the safety prime.
As far as your list goes, don't forget the safety prime and the Auto Disk riser at a minimum. Get the Safety prime that comes as a large and small primer kit. It's a great primer and really speeds up the press. No need to prime off press and slow things down, especially with pistol, where you're not trimming.
Hope this helps,
Dave