If you're going to use the 10mm in a Glock, note first that the Glock is not recommended for cast bullets in a factory barrel. A new barrel from Lone Wolf for $99 would make cast bullets feasible and, if the gun will feed them reliably, that would be my first choice. If you're going to use a factory barrel, you would probably have to go with a 200 gr. FMJ bullet, again loaded hot. Last choice in the 10mm would be a 200 fr. FMJ bullet factory load. Avoid anything that will expand like the plague. Having said all this, I have to agree with Iggy. I've used the 10mm for years and I have a lot of respect for it. If I had to use an autoloading handgun for bears, that would be my choice, probably in a Glock because of the extra rounds. But it wouldn't be my first choice by any means. I'll just leave it at that. Good luck.