For a melee weapon. Sorry for not elaborating.
Well, it’s not like we can give you any units that’d be very helpful. Why not just decompile the model import it into your modeling program?
Import a soldier and see? Best if he is in a good pose too, with hands in battle position if possible so that hand(s) will be a fist. I had done this when I needed average human size to resize my car so I imported it in a sitting position with hands on steering wheel.