This pistol favored by Malcolm Reynolds was a Moses Brothers Self-Defense Engine Frontier Model B produced by the manufacturer Moses Brothers Firearms. This weapon—like Mal's fellow soldier Zoë—was with Reynolds throughout the Unification War.
The weapon featured two distinct firing systems, a newtech Gauss/Coil gun carriage and a conventional hammer based firing system. The default for the gun was Gauss mode but the switch over to certain conventional shells was immediate. The Gauss Carriage was powered by a hefty battery in the gun's handle. This led to one of the weapons drawbacks, weight. The primary ammunition was NEWTECH Gauss Quadloads favored both for their punch and small size. The unique aspects of Gauss firing allowed for multiple shots to be carried in a single case.