(two different types at least, one for the garand, one for the savage)
I'm not a mind reader, but I'd guess your .30-30 is a savage from your original post.
Anyway, the die resizes the brass as the press forces it into the die. The die is adjustable (a little) so you can get the correct headspace. (Use the THR Library to look this stuff up.) However, you still need a die for each caliber you are trying to reload. The internal dimensions have to match the cartridge, that's all.
As far as reamers go, this isn't really a reloading tool in my experience. I've heard of finish reamers used by a gunsmith to machine the correct headspace in a new barrel he has just mounted to an action. The barrels are usually sold by the barrel mfgr as "short-chambered" so the gunsmith can do this after he's threaded it and mounted it.
You may be referring to primer pocket reamers, which are used in reloading.
Your SKS uses .311 diameter bullets, I believe. 7.62mm is a general term used to describe cartridges. 7.62 NATO and 7.62x39 don't both use .308 bullets, believe it or not.
However, the .30-30 and .30-06 do both use .308 diameter bullets.
I reload for my Garand with Hornady 150gr FMJ to create a "close to military" round, and I can switch to 150gr Hornady SST's and use it for hunting. I have an adjustable gas nut so I can use "non Garand loads" without damaging the operating rod.
I see that Hornady is offering special match ammo tailored for the Garand. Golly is it expensive! I'm glad I reload.
I use a Dillon 550B progressive press for reloading rifle rounds, even though conventional wisdom says you need a single stage press. The advantage of the 550B is that it has manual indexing, and this allows you to do the depriming/resizing, remove the brass for cleaning off the lube, then resume the operations with a box of cleaned, primed brass. You just index past the first stage before pulling the lever...
In addition to the press (whatever you choose), I believe you will need the following tools -
Dies and shell holders for your calibers
powder measure
powder scale (I'd go digital here..balance type are really, really time consuming)
6" vernier calipers, dial type (no need for digital, dial type easy to read)
some type of case lube, possibly a lube pad
case trimmer and appropriate pilots for your calibers (cases tend to get longer when resized and this is bad)
case headspace and brass overall length gauge (Wilson makes one type)
repriming tool if your press doesn't do it
reloading manual (Speer has a good one, as does Hornady and many others)
And, of course, the following components -
brass in your calibers (.30-06 and .30-30)
primers (I believe both calibers use Large Rifle primers...please verify)
powder (Hodgdon lists loads for H4895 and Varget for both calibers, so you
can use one powder*)
bullets
* I believe H4895 is considered traditional for Garand reloading, and Varget may be too slow without an adjustable gas nut. Please verify.
Good luck!