How to count the buff on gun or stuff

i got a gun , base is 52, it boost +40, and +10 critical damage , +40 melee attack/ or close attack ,jakobs.

in shooting range, hit the body got 54( from +4% boost, confirmed), headshot, critical hit, 133?? or 2.48 times of base, 52. so how to get 2.48, i can’t figure out how to get this number 133. i got only +40 weapon damage, +10 critical damage…

Maybe this will help: