30 caliber.
35 for 338
375 for 35
You can buy ONE die with the threaded stem and buy the individual expanding plugs.
I use the Lyman ones. By a "long" M die. (really designed for expanding necks for using cast bullets)
http://www.midwayusa.com/product/194950/lyman-neck-expander-m-die-405-winchester (these were not made when I started doing this, hence I used a 41 Magnum pistol die)
The actual expanding "plug" is threaded onto stem that goes through the die body. You can buy additional "plugs" in various diameters directly from Lyman.
Say you wish to build a false shoulder on a 300 Win Mag, buy a 32R or 33R plug, unscrew the 405 Winchester one from the stem, replace it with the 32R or 33R one and you're ready to go.
Die bodies for handgun calibers are called "short", they will work but the ram will only be partially raised and it's easy to go too far.
Here's another site with some good pics and tables: (you can use a "pistol plug" on a "long" rifle die as the threads are the same). The tables are dated as there are more plugs available today.
http://www.lasc.us/Brennan_LymanMDies.htmAs Joe says, Lyman is a nice place to do business with.
Sounds a lot more complicated than it really is. Good luck !