Say I am a Spellslinger 1/ Eldritch Archer 7 with a +1 gun, and I use Spell Combat and Ranged Spellstrike to cast Gloomblind Bolts at a foe, shoot one of my bolts through my gun, and I roll a natural 20 and confirm the crit.
Does my +1 gun give a +1 to the save DC?
Does the bolt have a x2 crit, like Eldritch Archer says, or x3, like Spellslinger says?
Yes to both.
Awesome. I wasn't sure if the Arcane Gun stuff would stack with Ranged Spellstrike or not, since they seemed like they may be two distinct actions.