What special abilities for guns and/or ammo do you find work the best for guns? Pistols or otherwise. My character is actually a Mysterious Stranger (Gunslinger) 1/Divine Hunter 2 (Paladin) right now. Very, very fun. I'm imagining sort of Magiktech Guns or Holy Guns of Righteousness.
Later on, like with arrows, +1 Bane bullets of varying flavors are very nice. Being able to swap in Human Bane or Undead Bane onto your weapons on the fly is fantastic.
I use a merciful +1 pistol. rubber bullets, I also use Admantium bullets, cold iron bullets and Silver bullets. the best so far has been ranged it increases the first Range increment so you hit against touch ac at 40 instead of 20. besides that it is up to you.