Although it appears to be a conversion, the 1871-72 Open Top model was
Colts first revolver specifically manufactured to fire a centerfire
cartridge by incorporating the loading gate in the frame. Since Colt did
not use percussion revolver parts, the revolver was manufactured as an
entirely new model, first with Navy-sized grips, later with Army-sized
grips. The Hickok model is a modern twist on the classic Open Top that
features a snub nose barrel. This model features a case-hardened forged
steel frame, round barrel with front blade sight, no ejector rod, blued
steel grip parts, an Army-sized walnut grip, and a rear sight notch on
the rear of the barrel.