Capo pistol

The Capo pistol has been seen in official screenshots.

Rockstar has not shared more about the Capo pistol yet. This page grows as new trailers and screenshots come out.

More handguns

ES9
Seen in the Ultimate Edition screenshots.
K17
Seen in the Ultimate Edition screenshots.
Morgan
Ultimate Edition
Seen in the Ultimate Edition screenshots.
Mustang .357
Seen in official screenshots.
Nipper .38
Seen in official artwork.
Pistol
Seen in the first trailer. Earlier in games including GTA IV, GTA Chinatown Wars and GTA V.