In a lot of ways, gunslingers are glass cannons. Sure they hit hard and fast, but they have magic-user hit points and can't take too many hits themselves.
While they might not be as tough as a professional blue coat, nobody wields the irons quite like an honest to god, bonafide gunslinger.
Level HD BHB Save
1 1 +1 15
2 1+1 +2 14
3 2 +3 13
4 2+1 +4 12
5 3 +5 11
6 3+1 +6 10
7 4 +7 9
Gunslingers are proficient in hold outs and pistols.
Quick Draw: Gunslingers are faster than lighting on the draw. When determining initiative, the gunslinger's party gains a +1 bonus. This bonus increases by one at 3rd and 6th level.
Back up: Eventually gunslingers learn that sometimes it takes more than your trusty iron to save your life. At 2nd and 4th level they can choose another weapon to gain proficiency in.
Two Gun Kid: At 3rd the gunslinger learns to fire two pistols a turn. They have a –5 penalty on the second attack.
Also, these guys would be perfect two-gun pulp heroes if you want to go that route in Light City.