Gunslinger

Gunslinger is a Fallout 3, Fallout: New Vegas and Fallout 4 perk.

Effects
While using a pistol (or similar one-handed weapon), your chance to hit in V.A.T.S. is increased by 25%. As with all perks that increase your chance to hit in V.A.T.S., this bonus is multiplicative, not additive.

Affected weapons in Fallout 4
If a stock is modded onto any of these pistols, they will no longer be affected by the Gunslinger perk.
 * Plasma Pistol
 * 10mm Pistol
 * Pipe Pistol
 * Pipe Revolver
 * Laser Pistol
 * .44 pistol
 * Kellogg's pistol
 * Pipe Bolt-Action Pistol
 * Deliverer