How is damage and downing people calculated

Hello, I have 2 questions.

  1. Is damage to the enemy soldier based on the part of the body the bullet hits. Ofc the headshot is the most deadly, that is clear, but does the game distinguish a foot shot or groin shot from a heart shot or stomach shot etc.

  2. When I use the Winchester rifle on Stalingrad I seem to instakill 100% of enemies hit and not hit in the head. But when I switch to any other rifle, lets say SVT 38, the rifle seems to only instakill around 50% of the time. Is there some metric that decides if the target gets downed and i have to shoot them again instead of them getting instakilled? Like the part of the body shot, which gun I used to do it? Like, does the Winchester have a secret ability to instakill that the SVT doesn’t?

Yes

All Bolt-action only in stalingrad have OHK permanent activated, in other campaigns hig damage Bolt-action can OHK, low-end Bolt-action sometime need 2 hit for kill, semi-auto are tricky they almost all time need two hit for kill