I've killed 5 deer, one antelope, and one elk with the 300 grain XTP mag .452 bullets. I cannot complain. I found that through my rifle and pistol the 300 grain did a better job then the lighter grains.

I'm no expert, but the .452 300 gr XTP ( non magnum) will perform very well if the FPS are kept in the range that the bullet was designed for, and that's less that 1600 FPS. If you want a bullet (that almost the same) that will hold together better, than go with the Speer Deep Curl which can be shot at much higher velocitiy.

The XTP Mag was built for higher velocities and holds togeather better than the regular XTP.
(BP)

I have used the .40 cal 200 grain XTP on multiple deer, and my hunting buddies exclusively use the .45 cal XTP in both 240 grain and 250 grain. Between the 3 of us we've probably taken 75 - 80 deer in the past 10 years with these bullets (mostly with the .45 caliber versions).

Our experience has been that the XTP is a very good bullet for deer hunting, with maybe one exception. You need to be careful about how fast you push it - it sometimes has a tendency to come apart at high velocities. Generally when this has happened, the deer still dies quickly provided good shot placement, though. I don't think we've ever lost a deer due to bullet failure- we've only lost a handful of deer, and that was due to poor shot placement.

We've used powder charges in the 70 - 100 grain range with good results.