I'd add too the value of being able to change up the old line: I shoot a .45 because they don't make a .46
I asked every gun store I walked into (every couple weeks) for a year if they had any 41 magnums and all I found were a couple abused wheel guns. My understanding is that, in the way of muzzle energy/FPE, stout factory loadings (e.g. Underwood) of 10mm are more powerful than those of 45 super. And the same goes for both 460 Rowland as well as 41 magnum with the cartridges loaded to their capability are more powerful in FPE than those of 10mm. 460 vs 41mag is an interesting comparison. It seems without +p the 41 mag on FPE does not claim a title.
But I don't think it's as simple as FPE. The FPE has to transfer to the target and in the right places. I would think the 45 caliber of 460R over 41mag's ~43 caliber or 10mms 40cal would transfer that FPE into the target more quickly, with less chance to over penetrate and the bullet leave with energy still left not transferred. But, bears hearts beat very slow and they might not be deterred by flesh wounds/pain. I think the bear central nervous system as a target would be the closest to a reliable way to survive. To penetrate into the bear, would the .45" be the best choice or would it lose energy too quickly? I understand this is where sectional density comes in - the bullet may have to displace more tissue to penetrate but if it has a higher relative weight to the more narrow projectile it's momentum can penetrate. 10mm seems to top at 200gr. 460 can use 45acp bullets and plenty of 255gr hard cast around.
I got some of the 460 ammo already Here is a poor photo of Underwood 460Rowland 255gr flat nose hard cast next to their 45acp +P offering with the same bullet. You can see the 460 has a longer case (1.4mm) and also Underwood apparently doesn't have access to nickel plated 460R brass
Anyway I feel like I have an autoloading 41 magnum coming in the mail, and it happens to be inside the FN FNX45 Tac that I've always wanted. God Bless America!