PERK2 POTERE D'ARRESTO

Increases weapon damage to 140%, however no increase in wall penetration. This is a great perk to use together with accurate guns that don't do much damage.

For guns with low damage such as the M4 this is a great perk, eliminates juggernaut and to everyone who’s not using juggernaut it just does 40% more bullet damage. Does not increase surface penetration, by definition, but think about this. Let’s say a bullet does 40 damage normally, and after surface penetration does 30. With stopping power, it might do 60 damage normally, but after surface penetration it does 45 or so. So not by definition, but indirectly it increases surface penetration.
Stopping Power is available by default.