The Ruger Vaquero was originally designed as a fixed sight version of the Ruger Blackhawk. It’s a single action only revolver that looks incredibly similar to the Colt Peacemaker revolver, with the main difference being that the Vaquero is a bit beefier and further lacks the half cock feature, as the cylinder is freed by simply opening up the cylinder.
Later, Ruger decreased the frame size of the Vaquero with the New Vaquero, which has much more similar dimensions to the Peacemaker. The New Vaquero is today offered in chamberings such as .357 Magnum and .45 Long Colt. It’s also a very common sight at cowboy action shooting events.