Kam... thankfully I was on federal land. I have nothing good to say about CA state gun laws. But the rangers on the federal land were actually ok w/ me carrying, which is to their credit. They were actually incredibly helpful planning the hikes.
Lance... yes, I do think that 10mm would fair significantly better then .40 or .45 in application on a bear. When I compared the ballistics info 10mm was just slightly below the curve on some of the hunting calibers (handgun). A 10mm round is just a .40 with a good deal more powder behind it. .40 actually has the best one shot stopping power of any round (actually better then .44 mag). Again, it really varies based on manufacturer/round selection as shown here:
http://www.internetarmory.com/handgunammo.htm
(FederalPremium.com has a great compare feature for the ballistics charts on their different ammo so you can do a compare of different specs or different calibers)
The benefit here is that Mass x Velocity = Force (yes, for all you purists out there the formula is actually F= MA but since A= (vf-vi)/t I thought I would go with it for simplicity's sake. And yes, I know there is much more to this (bullet mass, change over time, etc)). Added to that are the diameter issues which are important for the wound channel.
So with 10mm you have a pretty meaty cartridge going at a fairly nice clip (compared to .45 which is only .05 inches bigger in diameter (11%) but goes 200-300 fps slower (especially @ 50 yd and 100yd measurements) which is a difference of 20-30%). Again, this varies widely depending on manufacture, etc (and yes, there may be a huge swing in bullet mass depending on ammo choice which is why I did not touch that here).
Think of it this way... what is the difference between .45 ACP and .454 Casull? About 4 one thousands of an inch wider and .02 of an inch longer and a heck of a lot more powder. And .454 is what they actually use for hunting bears. All things being relatively equal, powder equals speed. Same goes for .40 vs 10mm.
So, all things being equal, .454 Casull has one application (I almost broke my wrist shooting it!
) but 10mm can still be used at range, home defense, etc. So, while a true hunting cartridge would be better on bears, I'm going to go with something a little more versatile but still packing enough to hopefully make the bear move along.
I will preface that by saying, with the exception of the math, everything above is my opinion... I don't know any real world data for how 10mm would do against a bear. (And I hope I never find out first hand).
Once was enough thank you! But the data is compelling enough for me to make the switch... b/c I know neither my .40 or .45 would cut it. Thx for the question Lance! God Bless!
-MonkezUncle