Increase threshold for damage stacking

Right now, as is, you need to hit shots very consecutively together for damage vaçie stacking to work properly (on both modes), otherwise you'll get a bunch of staggered damage numbers. Given that not everyone who plays this game is god-tier at aiming, I think there should be a bigger threshold (somewhere around 500-750 miliseconds) between hits on players before the damage stacking stops working. It'd be more consistent and more people wouldn't have to make excessive calculations because they missed a few shots.