dynamic is most important for any gun that has it as an attribute
Vortex, go for crit, then reload, then fire rate. I made mine with max fire rate first, and will be remaking it eventually. Reason being, the special shot does not charge up during reloads, so right now I can pop off shots really fast, but reloads are slow, so I hardly have time charging up my special shot. I'd rather have less downtime, and the base fire rate is pretty decent already.
Caliber is base damage. Important stats are crit chance > caliber > crit damage when those are the options. It will ALWAYS do more damage than Crit chance > crit damage > caliber, through testing.
Or if the gun has hero killer, exterminator, and caliber, it's up to you. You can max Caliber and one of the others to deal a ton of damage to a certain enemy type, like bosses and players, but if you max HK or Ext, the 15th point in those gives a huge boost to their %, so maxing those 2 and putting the rest in Caliber gives you a nice even damage boost to EVERYTHING you shoot at.
I think the totals are like 100% extra damage to a certain type, with like 60 or 70% to what's left, if you max caliber and one of the special ones. Or you can get like 80-ish % to everything if you max HK+Ext with leftovers in Caliber.
This is all assuming you are max forge, of course.