Depends on the exact weapon
Depends on if you are talking about military or civilian and what "strongest" means to you.
Ruger No 1
What is usually the strongest of a bridge
Suoer Augilla 22 LR
The flight muscles are the strongest in musculature.
the strongest part of a soccerball is where you pump in the air that way if you kick it there you will get alot of effect
The strongest part of a hurricane is the eyewall, just outside the eye.
your teeth
The chassis.
its exoskeleton
leg
It is the eyewall.