Although, come to think of it, a variance between 6 and 7 damage for the knife makes sense as (20/3)
so (for your values of HP, not the "damage" I've been getting, I would predict
So the knife hits for 20 (2x headless, 4x zombies, 5x ghouls, 12x ghasts, in my experience--although why ghasts wouldn't require 11 stabs I don't know. Trust me, I'm stabbing a lot of them these days, though.)
blue crystal (BC) is 25
P4 (at expert at close range) maxes out at 36
OC is 50 (Nightmares can be killed with OC + 1 P4 = 86)
mp41 maxes out at ~65 or so? (I think you can four-shot oozes with these)
Violet Crystal is about 100, ditto the SABOT?
HE grenade is like 1,000?
and you can tell where I stopped researching this and started grimly making grenades and SABOT rounds.
I would be delighted to know what goes into the damage ratio the game offers. All I know is it includes the full value of the last hit that kills (whether or not the monster only had one hit point left--you get 320 points of damage for an HE round, whatever it kills) and doesn't include crystal damage. And really doesn't like edge cases.