Hey no dis on your favorite cartridge but the reloading books are not actual data by a far stretch.
Underwood loads that 180gr XTP to 1300fts in a 10mm a similar 40cal load is 1100 fps
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Also, no one said anything about poly barrels so I see no reason at all to bring them into a comparison of calibers. That is firearm design and is a concern when using soft lead bullets not hard cast and not jackets. Both calibers are readily available is different types of rifled barrels.
If I person wants a gun for bears, the 10mm is an excellent option. Is a .40 good enough? Maybe. Is a 10mm a lot more powerful than a .40? Yes, about 25% faster and 50% more energy. Are most current factory 10mm loads anemic? Yes is a 10mm the best caliber to hunt bears with? No. Is tge 10mm more powerful than all other handgun cartridges? Not by a long
The choice of bear pistols is always going to be a personal compromise between weight, power, recoil, speed, reliability, etc.
Personally I think a person is far better off with a gun they ate familiar with and practice with than a cannon they aren't/don't.