MOST IMORTANT PART
first thing you want to do is get shoot and take aim at lvl 5 (lvl 4 is ok but i recomend 5) take aim is mainly for blunderbuss because it gives u maximum damage when looting and of course shoot is for pistol if u want to pick your style.
SECOND MOST IMPORTANT
second thing u want to do is to get silver and steel shot at lvl 5 (5 is recomended and there should be no exceptions if u r following this guide by exacts)
just in case u run out of ammo have bane shot at lvl 3 (optional)
and if you r a low lvl and u r fighting gypsy bosses get hex eater shot at lvl 3 (optional
(if you are useing a pistol lvl 19 and below get bane shot maxed out as well as hex shot and get poison shot at lvl 4/5)
now use your remaining skills on your favorite passive skills
NOW GO KICK SOME TAIL