I finally found a local supplier of 10mm ammo at Alaska High-Performance Ammo (http://alaska-ammo.com/). Great guy, it also turns out he's on the forum as AKrstabout and is the sponsor of the Ammo Dump forum, which I didnt even realize was there. Saved me a bundle.
Now that I have it I'd like to know if alternating hardcast slugs with hollowpoints in my 15 round magazines is a good idea for bear defense. The gun is in a chest holster so I can get to it quickly and I'm a decent shot.
The idea is to have the hardcast 230 grain for deep penetration/kill with 180 grain hollowpoints for soft tissue damage and "sudden impact" that would make a bear pause (so I can put more lead into him), I dont know if the hollowpoints would do any good though.
Something else to think about is that the recoil of the two different rounds is very different, the hardcast 230 has a pretty stiff recoil (750 ft./lbs muzzle) and the 180 hollowpoints not so much (620ft/lbs)
Every weekend during the season I'm in the middle of nowhere in waders and (hopefully) have a string of bloody fish on a stringer so I'm a prime target for bears.
I've already had a couple minor encounters with small blackies but they've run off when I yelled at them.