As far as die sets go its really a personal preference and/or needs. The four die set usually has a full length sizer, a bullet seating die, neck-seizing die, and a crimp die. The neck sizing die is usefull in bolt guns and single shots. The case is "fireformed" in the chamber, and then only the neck is resized, allowing a more custom fit. Doing this also works the brass less, and it lasts longer and also requires less trimming. I see some positive results in some applications, but not all. FWIW, you can neck size a case with just a standard full length sizing die also, you just don't screw the die in as far to work the body or touch the shoulders. The seating die is pretty self explanatory. A crimp die, thats another personal preference. I didn't crimp any rifle rounds for years and never had a problem, never experienced any set-back, even with malfunctions. I do it now because I run a progressive and the station is there, so why not. I dont see a difference either way, but it does add some insurance I suppose.
As for the brand of die....again, what fits your needs. You don't need a redding competition seating die, even though they are nice. I'm partial to Lee Dies. I love the lock ring on them, and more importantly the adjustment knobs. That, and the die sets come with load data, and a shell holder. I was in a hurry one time and barely made it to the store before they closed, and all they had for 30-30 dies that I needed were RCBS dies. I got the dies, came home, ready to load, and WTF!! no shell holder! I was soooo pissed. I mean, who sells a die with no shell holder? Your dies are useless without the shell holder, is it going to kill RCBS to pitch in a 3.00 shell holder with their die sets? It's like buying a drill and then having to buy a chuck key for it or something. That and adjusting them is a PITA, little dinky slotted stem with a small lock nut, you have to hold the stem still with a small screwdriver and loosen the lock nut....ugh. Lee dies adjust as simple as turning a radio knob. Im not a fan of RCBS, though many people love and use them with great success and they will do a fabulous job. Back to that whole personal preference thing.
You didn't mention it, but another tool you will need is an inside/outside deburring tool to deburr and chamfer the inside/outside of your case necks after trimming. Lyman sells a great all in one tool that has the screw in attachments for cleaning large and small primer pockets, reaming large and small primimer pockets, and deburring/chamfering inside and outside of case neck. The handle stored all the attachments, its a comfortable tool to use and does a very nice job, and its very affordable at less than 20.00. Its a steal for all that it does.
The link posted above my post is the tool I was talking about.
