Rose,
It's kinda hard to answer that question. If you are not going to practice with the ammo you are going to use for serious purpose then you have to look for something kinda custom.
Example. If you are going to use wizbang brand 125 gr HP at 1,000 fps for serious use you need to match the balistics of that rond so you get roughly the same point of impact / aim for both kinds of ammo. That means getting the same weight projectile and the same velocity perhaps in a hard cast lead bullet. If you are not going to handload that might be a bit hard.
If you use a common "reman" batch of ammo to practice with, chances are it will have a heavier lead projectile. (158 gr is common) That means it will shoot to a different point of aim. It kind of makes the practice a little less usefull than it could be. If you do go that route get 2 boxes of the "good stuff" and shoot very carefully at the end of the session with it to make sure you know where it's hitting.
