All good answers so far. I load .44 mag. and have done the 300 gr. XTP. But, for self-defense I would choose a round that has less recoil. The .44 mag. at it's least load is quite a bit for SD. I would choose a 180 or 210 gr. bullet and find a moderate load.
The max-max loads with 300 gr. bullets are heavy recoiling and, for me, very tiring to use. Plus it takes more time to bring back down on target making is less suitable for SD.
For bear, just hope he isn't too close for that second shot to get placed properly. Shooting at the sun isn't going to save you from bruin.