Your vote should go to the minimum pistol round, from a non-speciallty "full size" pistol (4"-6") that you think will beat a well setup bow at 40-50 yds, for leaving an elk/deer "hoof side up" without much of a chase.
Bow guys say no way.
Handgun guys say are you crazy.
Here's what I have experienced, I shoot fixed blade Thunderheads since first day they came out in 80's and never killed another deer with another broadhead. They fly great with the RIGHT spined arrow and out penetrate any mechanical ever designed. My son and I shoot 60 yds easily with them accurately. I have a 100yd archery range in my backyard so we know how to set up our equipment. So my experience is a 450+ grain arrow with 100 gr Thunderhead will blast thru pretty much anything. My son shoots 82# 500 gr at 305fps and it is unreal what it will go thru.
I have handgun hunted for lot of years and killed a lot of deer with both .44 Mag and 35Rem.
So how do you compare two different lethality's at 40-50 yards? A proficient archer versus a proficient handgun hunter?
You don't
At 40-50 yards a 60# bow, 450 gr arrow with fixed blade broadhead will still pass thru elk. A big bore handgun will get the job done too.
Dead is dead ... period.