PSM is the first Pistol accquired in Bioshock: Unlimited.
Standard Pistol Rounds- Main Ammo, Same as the first
Shatter Rounds- After five shots Freezes a Enemy for 5 seconds, Rarest Ammo for gun, And can only be bought
Scatter Rounds-Fires Slower, But fires 3 Bullets at once, Only Found around Lasmoore, Not bought
Scope + Accuracy Increase- A classic Scope added on
Boost- Can put enemies on fire with Standard and Scatter Rounds
Speed- Faster Firing and Reloading