I have never shot anything with any of the T/C maxi conicals, but have seen deer shot with the maxi hunters. I personally dont think they expand very much, if at all. I also think the Buffalo Bullets and the Hornadys are a little softer as well.
I havent had a gun yet that would shoot the T/C's as well as Buffalo Bullets or the Great Plains. I have tried them in 6 or 7 at least.