I'm in the process of 2 new builds to submit.
One is a Gunslinger/Alchemist/Inquisitor
The other is a Gun-Fu build, relying mainly on Gunslinger and Monk.

The Alquisinger (need a useable name)
Gunslinger 5/Alchemist 3/Inquisitor 12

Archetypes are chosen more on what we DON'T need from our classes:

Musket Master, yes, Musket Master. You'll see... you'll see...

Vivisectionist, we don't plan on using Bombs, and only need 11 Int for Extracts anyway.

Spellbreaker, Teamwork Feats aren't the best for Ranged attacks, and the Save boosts are nice.
Black Powder Inquisition, we regain the use of all Firearms, and any caster we hit gets a penalty on Concentration checks (although most any Inquisition/Domain will do)

Gunslinger 5, gives Rapid Reload as a bonus feat, lets us Reload Muskets faster, and Dex-to-damage with Muskets.
Alchemist 3, 2d6 Sneak Attack, optional +Dex/-Wis Mutagen the Discovery will be Vestigial Arm (and we'll grab the Extra Discovery Feat for the 2nd extra Arm)
Inquisitor 12, the main draws here are Greater Bane for +2 to-hit and +4d6 damage when we want it. We get 2 Judgements at a time, we will be using the +5 damage option the most, the other depends on the situation (Fast Healing 5, +3 all Saves, [choose an energy] Resist 10, and/or Bypass Damage Reduction). We also get 4th level Divine spells, and Stalwart (Evasion for Fort/Will)

Race is currently up for grabs (will finalize once the build is farther along)
Human, +2 any, Bonus feat
Half-Elf, +2 any, 2 favored classes
Drow Noble (yeah right...only if we volunteer to be our DM's Slave for 3 months....)
Tengu/Udine for a Medium race with +Dex/+Wis

Basic strategy:
Dual Wielding Muskets, HOO-RAH!
Stacking as much bonus damage as possible (Sneak Attack/Bane/Judgement/Dexterity)
We also wind up with a lot more Skill points than a typical Gunslinger, and 4th level Divine spells. I'm sure I can think up something to do with them...

Gunslinger ?/Monk ?

Gunslinger will be either Pistolero or Musket Master
Monk will be 'normal', or probably Zen Archer (for the Ranged bonus feat list, and free Point-Blank Master at level 3)
The idea with taking Monk is that we get Wis-to-AC (Touch AC at that), and get decent Unarmed damage, combined with taking Combat Reflexes, to be a passable Melee threat as well.