Howdy
The Vaquero is absolutely not a clone of the Single Action Army. Clone, or replica, means the internal mechanism is the same, or almost the same, as the original. The lockwork (mechanism) of the Vaquero is radically different from that the Single Action Army.
Let's step into the Way Back machine for a moment. Ruger introduced their first Single Action revolver, the 22 Rim Fire Single Six, in 1953. In 1955 they introduced their first Center Fire single action revolver, the 357 Magnum Blackhawk. The internal mechanisms of these guns was very similar to the mechanism of a Colt. Like a Colt, they had three cocking positions on their hammers, 'safety cock', half cock, and full cock. The cylinder was free to spin for loading and unloading when the hammer was placed at half cock. And just like a Colt, if you whacked the hammer hard enough with a live round under the hammer, they would fire. The biggest innovation of the Ruger design was substituting coil springs for the old leaf springs of the Colt. Using coil springs increased the parts count because each spring needed a plunger, but the old Three Screw Rugers, as they were known, operated exactly like a Colt.
This big Three Screw Flat Top 44 Mag Blackhawk was made in 1957. If you look carefully you can see the spring plunger for the trigger just behind the trigger.
In 1974 Ruger completely redesigned their single action revolvers. A transfer bar was added to the design. With the transfer bar, the hammer never strikes the frame mounted firing pin. Instead, when the trigger is pulled all the way back, the transfer bar rises up and positions itself so the hammer will strike it, and the transfer bar transfers the hammer blow to the frame mounted firing pin.
This photo shows the hammer of a Vaquero fully cocked, and the transfer bar has risen up and is in position to transfer the hammer blow to the firing pin. The arrow points to the transfer bar.
In addition to the transfer bar, the new single action design did away with all but one of the hammer cock positions. The hammer now only had a full cock position. The cylinder was freed to rotate when the loading gate was opened. Hammer position had nothing to do with freeing the cylinder for loading.
The new design was officially dubbed the New Model. The reason for the changes was law suits that Ruger was involved in resulting from deaths and injuries from revolvers accidentally discharging when the hammers were struck. The New Model designs were and are completely safe to carry fully loaded with six live rounds in the chambers.
I purchased this 45 caliber New Model Blackhawk in 1975. It came with two cylinders, one for 45 Colt, the other chambered for 45 ACP. You will notice the Three Screws have been replaced by two pins. In the old design, the hammer, trigger, and bolt each pivoted on their own screws, just like a Colt. In the new design, the hammer pivots on one pin, the trigger and bolt rotate on the other pin.
The Vaquero was first introduced in 1993. It was nothing more than a New Model Blackhawk with the frame contours rounded off to resemble a Colt, and the adjustable rear sight replaced by a groove in the top of the frame. This model Vaquero, sometimes called the 'old model, or 'original model', was built on the same large frame size as the Blackhawk, so the cylinder was big and beefy enough to be chambered for 44 Magnum.
This is a large frame 45 caliber Vaquero of the 'old', or 'original' size. I forget what year it was made, but it is a pretty early one. The Vaquero did feature a steel grip frame, which made it slightly heavier than the aluminum grip frame of the Blackhawk. Notice the Vaquero has the same two pins as the Blackhawk. The cylinder pin on this gun is an aftermarket pin.
This pair of Stainless Vaqueros are also chambered for 45 Colt. The highly polished Stainless was meant to resemble the nickel plated guns of the 19th Century.
In 2005 Ruger ceased production of the original, large frame Vaquero and introduced the New Vaquero. As dumb a name as they could possibly have chosen. There has been more confusion to date over which is the New Vaquero and which is the 'old' or 'original' Vaquero than just about any other gun I can think of. To make matters worse, the catalog now lists the New Vaquero as simply Vaquero.
Anyhoo, the New Vaquero was introduced to satisfy the requests of many Cowboy Action shooters who wanted a Ruger more the size of a Colt. And of course, as soon as it was introduced, everybody wanted the 'old model' back. The New Vaquero is very similar in size to a Colt, and as such the largest caliber it is chambered for is 45 Colt. It IS NOT available chambered for 44 Magnum.
This photo shows the 'original model' Vaquero pictured earlier with a 357 Magnum New Vaquero right under it. You can see the New Vaquero is slightly smaller. the basic mechanism of the New Vaquero is the same as the 'original model' Vaquero, and the New Model Blackhawk before it. Same transfer bar, same loading gate controlling the free spin of the cylinder. This New Vaquero is an early one and has the high hammer spur that originally came with the model. The New Vaquero also features a spring plunger in the frame that causes the chambers to line up properly with the loading gate, always a short coming with the other New Model Rugers.
Here is a New Vaquero compared to a Colt, showing the similarity of size.
This last photo shows a Ruger 'old model' Vaquero cylinder in the center, an Uberti Cattleman cylinder on the left and a 2nd Gen Colt cylinder on the right. All three cylinders are chambered for 45 Colt. Notice how much more massive the Ruger cylinder is and how much more meat there is surrounding each chamber. That is why the large frame Rugers were so strong. I don't have a 45 caliber New Vaquero cylinder to show for comparison, but it would look very similar to the Uberti and Colt cylinders. Folks like to talk about the New Vaquero being able to digest heavy loads, but if I had one I would never feed it anything more powerful than SAAMI Max 14,000 psi loads.
YMMV.
