Quote from: Seraphine_HarmoniumNot sure how it would translate to Pathfinder, but in O.R.E, you'd add 3 to your dice pool and get a hit per matched set. You'd be assumed to use 10 ammo each time you did this.
Maybe say you can make a LOT of attacks, all at a penalty?
I would suggest treating guns like a tommy with full-auto and such as having the option to make spread attacks, IE requiring a Reflex save. Also, you can look at the d20 modern book for suggestions.