The 450 Marlin is kinda sad.
http://www.hornady.com/store/450-Marlin-350-gr-FP/e 450
How bout this... a 416 Remmington Magnum. It hit's twice as hard as the 45-70. That would be serious stopping power. Instead of just making the bear really really mad, you actually make it dead... and then that means that you are still alive standing there before the magnitude actually sets in.
http://www.hornady.com/store/416-REM-MAG-400-GR-DGS/
The Winchester .338
http://www.hornady.com/store/338-Win...Superformance/
Serious stopping power... the 416 Rigby
http://www.hornady.com/store/416-Rigby-400-gr-DGX/
Here's the 45-70, it's kinda sad
http://www.hornady.com/store/45-70-G...EVERevolution/