Small based dies are designed to resize cases for cycling through semi-autos, and as such, they resize the case a little tighter than regular dies, at the base of the case, where some regular dies don't really get to. There would not be a problem with cases resized this way for bolt guns, except that it can really limit overall case life, and can lead to premature casehead separation. It can also work harden the brass much faster, leading to case neck splits and such. The idea is, from a handloading standpoint, only resize as much as you have to, to get the cases to chamber correctly. If you have only one bolt gun of that caliber, and all your brass will be used in that gun, I suggest getting a neck sizing die (I like the Lee Collet dies, personally, if they are available in your caliber) and resize only the neck of the case. If you have multiple guns in the same caliber, you can segregate your brass, or you can resize it all full length. I recommend segregating, and not bumping the shoulder back on your cases (set your full length dies to just touch the shoulder, but not move it back) and you will extend case life almost as much as using a neck die. Of course, if you're segregating, you can neck size for bolt guns, and full length size for autos and lever guns, and be well on your way.
