The Grumpy Grease Monkey mechanical engineer.
notice they stated they had a great many body hits fail to penetrate the bears vitals with the handgun ammo being used.,
yes both the 10mm and 44 mag have been successfully used to kill bears and successfully used in self defense
,Id point out , after reading years of reports,two basic facts are obvious,
your chance of being attacked or mauled is very very low,
and if attacked ,that in most cases you'll be forced into a very close range confrontation ,
under a very limited amount of time on a fast moving attacker,
Id doubt you'll have time to place more than 3 shot's maximum,
and your life might depend on the results of a single hits lethal damage.
personally Id prefer the 44 mag revolver with a 300 grain hard cast bullet over 21 grains of H110 powder,
but I would certainly not feel defenseless if all I had was a 10mm pistol,
there are 180-200 grain hard cast bullet loads over about 10 grains of blue dot, have worked well on hogs, and deer
(CHECK YOUR LOAD MANUAL)
keep in mind no handgun has near the stopping power of a 12 ga slug,
or a 45/70 or 450 marlin with a hard cast 400 grain bullet
keep in mind its a knowledge of the opponents anatomy,
your skill at accurately placing shots under stress,
and precise shot placement more than power or magazine capacity,
that makes ALL the difference
below some vaguely related videos
below some 44 mag related info, notice hard cast 44 mag revolvers far out perform the typical 10mm,
but realistically if your going to be shooting in a defensive confrontation,
you'll be lucky if you can get off more than 2-3 reasonably well aimed shots,
so magazine capacity .
while mentally it might be comforting its all but meaningless under real conditions.
as a defensive cartridge a 10mm is in my opinion close to ideal for a human opponent,
but it is certainly a bit less effective on a bear that might be significantly larger and much more heavily muscled.
I recently read of a fishing guide that carried a glock 10mm,
who was mauled and killed in ALASKA ,
they found he never got off a shot because,
he had never chambered a cartridge,
and he died with a full magazine.
witnesses stated he was attacked at very close range ,
unexpectedly , he drew his pistol but never got off a shot