bigclubs, a standard two-die full length sizing die set is all you'll need to make very good ammo for your .308 Win. cases. The sizing die's used to push out the fired case primers and resize it back to about factory dimensons. The other die's the bullet seater, used to seat bullets; just don't screw it too far down in the press or it'll start crimping the case mouth onto the bullet; bad stuff for best accuracy. I'd stay away from neck sizing dies as you'll still have to use a full length sizing die after 4 or 5 reloads on a neck only sized case anyway.
I suggest you get a good reloading manual, such as the one from Sierra Bullets, then read all that stuff in it about handloading bottleneck cases. Learn the terminology, different die uses, setup and use procedures.
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