Originally Posted by dkf
Whew just so the sectional density is close. They must be equal then.
Well a 147gr FMJ will penetrate through a deer and the diameter is only slightly smaller at .355" vs .401" so it must be ok.
Um, yea... a 147grn fmj 9mm would probably have no problem penetrating through a deer. I mean, if you don't think so I'd guess you really don't know how sectional density works for non expanding projectiles. Same reason .357 with hardcast has been successful on deer. Doesn't take much energy to penetrate far when bullets aren't expanding. So as far as deer are concerned, they won't know much difference. They are not hard to kill.
You probably can't come up with any good reason why the 10mm is not suitable for deer, you should probably just quit wasting your time.