I kinda depends on how hard of a hardcast bullet we are talking about here. They have a wayto quantify the hardness known as Brinell Hardness scale. Or something similar.

A very hard bullet is going to give you less leading at higher velocities and probably work better with the micro groove rifling. Also give little expansion on game. My experience in experimenting around with these in a Marlin 1895 is that as velocities approach 2,000 fps, you really need to start thinking about a gas check. They were a good inexpensive big bore plinking load at about 1800 fps.