And how does DR Modifier work exactly?
Your DR reduce damage you receive (with 30% DR you receive 30% less damage). The DR mod of ammo raise or lower ennemie's DR. For exemple, 5mm AP ammo have -35% DR mod, so if your ennemy have 50% DR, against this ammo the damage he receive will be lowered only of 15%. On contrary, if you shot him with 5mm JHP ammo, he will receive +35% DR, and he will receive 85% less damage.
Ok then i have question if its any cap to DR resist? (I mean in less than 0 like jet effect)
You can get -DR resist after Jet. But i guess you mean calculating for ammo
If your weapon make 10-20 dmg, and the ammo have a dmg mod of 3/2, your weapon when firing these bullets will have a damage of 15-30.If your weapon have 10-15, and the ammo 2/1 dmg mod, the damage will be 20-30It's as simple as that.
Does this means that a critical hit with .44 JHP can be quite devastating?