Here’s the Gunslinger conversion for Pathfinder Beginner Box. This was one of the more enjoyable conversions for me, maybe because I like guns in my games, even in D&D.
I’ve assumed early firearms and included stats for only three of them: pistols, muskets and the blunderbuss. Pathfinder doesn’t really differentiate between flintlocks, wheellocks and matchlocks, so they could be whatever you feel works best in your world (maybe they even use a (minor) magical ingition system).
I think tomorrow I’ll post a home-brew version of the Gunslinger, mainly tweaking the way a few of the grit deeds work. Otherwise, it probably won’t be a significant departure from the ‘official’ Gunslinger.