Well, I am new to the MZ thing, but not to bear hunting. I am also now shooting a T/C, and as posted above, the mmp 24 is the ticket. The yellow sabots that come with the Barnes TMZ's will fit, with serious pushing, but accuracy suffered, for me.
I then substituted the 24's, and WA-LA! 1" groups. Loaded MUCH easier, as well. Still takes applied pressure, but loads well. I was shooting 100 grains, (volume), of Bh209.
I have NOT killed a bear with a muzzy, yet. However, have taken over 2 dozen by other means, (center fire, bow, X-bow), as well as a couple of big brownies, and can tell you that every bear is different. Some simply die at the shot, other do not. MOST, not all, drop at a good shot, but big bears have a nasty habit of getting up and finding the thick stuff. Then you have to go dig them out. With a good shot, they are often found dead. Not always. When you find yourself entering thick stuff looking for a bear you just shot, you will find that there is simply no such thing as too much gun, or powder, or bullet.
Go big. Go accurate, and go confident.
May your bear drop at the shot, and stay there. It's best.