Howdy
The Rollin White patent for revolvers with chambers bored all the way through the cylinder so they could accept a cartridge loaded from the rear, expired in 1869. Previous to that time, Smith and Wesson had exclusive rights make revolvers using the concept of the White Patent. S&W paid White a $.25 royalty for every revolver they made. Which is why the Civil War, fought from 1861-1865 was mostly fought using Cap & Ball revolvers. Smith and Wesson was the only company legally able to make cartridge revolvers at that time, and the largest cartridge revolver they were making was the 32 Rimfire #2 Old Army Tip Up revolver.
This style of revolver was called a Tip Up because in order to reload, the latch at the bottom of the frame was depressed, allowing the barrel to
rotate up. The cylinder was then removed and spent cartridges poked out of the chambers using the rod mounted at the bottom of the barrel. Fresh cartridges were loaded into the cylinder, the cylinder was popped back into the frame, and the barrel was rotated down and latched in place. S&W never made any Tip Ups in larger calibers than 32, experimental models made for a 44 Rimfire cartridge were unsuccessful, the design was not suited for cartridges larger than 32 Rimfire. Although this method of reloading seems cumbersome to us today, it was far faster than loading a Cap & Ball revolver, and S&W could not keep up with orders for this revolver, many of which were bought privately by Union Army officers.
When the White Patent expired in 1869, S&W was sure the other revolver manufacturers would have their own cartridge designs ready for market. So S&W developed the Top Break revolvers and introduced the first one in 1869. Called the American Model, it was a much more advanced design than the Tip Ups, When broken open, an ejector rose up and automatically ejected the spent brass. Then fresh rounds could be loaded and the barrel swung up and latched in place, ready to fire. Notice unlike the Tip Ups, which rotated the barrel up to reload, Top Breaks rotate the barrel down to reload. This is a 1st Model Russian Top Break. It closely resembles the American Model, the only difference being the American Model fired a 44 caliber cartridge using a heeled bullet, the 1st Model Russian fired the 44 Russian cartridge with a .429 diameter bullet that was the same diameter as the
inside of the cartridge case.
During the Civil War there was a brisk business in revolvers converted from Cap & Ball to firing cartridges. Because the White Patent was still in effect, some of these Cartridge Conversion revolvers were converted by individual gunsmiths who did not have to worry about the White Patent. Remington had a contract with S&W to convert a large number of 44 caliber '1858' New Model Army 44 caliber Cap & Ball revolvers to fire cartridges. Remington paid S&W a royalty for every Cap & Ball revolver converted to fire cartridges.
Nobody was more surprised than S&W that Colt did not have a cartridge revolver design ready for market when the White Patent expired in 1869. The Colt Single Action Army cartridge revolver was not ready for the market until 1873.
Which after all this blabbing brings me back to the Colt 'Open Top' revolvers that were 'converted' to fire cartridges. The first of these was the Thuer 'conversion revolver'. This depended on a reverse tapered cartridge loaded from the front of the cylinder, clearly an attempt to get around the White Patent. This model was not financially successful and only about 5,000 were made.
After the Thuer conversions, Colt brought out the Richards Conversion. Patented in 1871 (two years after the White Patent expired). Basically the 1860 Army model Cap & Ball revolver with the cylinder reworked to accept cartridges loaded from the rear, and an ejection rod fabricated to replace the loading lever of the Cap & Ball revolver.
The nipple area of the rear of the cylinder was cut off, and a new set of ratchet teeth were machined from what was left. On the left in this photo is the cylinder from a Pietta replical 1860 Army Cap and Ball revolver, on the right is the Richards Conversion cylinder.
A Conversion Ring was screwed to the frame to fill the space where the nipples used to be on the cylinder.
The Conversion Ring had a loading gate so the revolver could be loaded without removing the barrel.
The Richards Conversion incorporated a spring loaded firing pin in the Conversion Ring and an integral rear sight. The hammer was flat faced to strike the frame mounted firing pin.
A new cartridge called the 44 Colt was developed for the Richardson Conversion. Using the the chamber dimensions of the 1860 Army a heeled bullet was developed that was inserted into the cartridge case. Like all cartridges with heeled bullets, the outside diameter of the bullet was the same as the outside diameter of the cartridge case.
The Richards Conversion was a financial success, being manufactured well into the cartridge era, but it was expensive to make. In 1862 WIlliam Mason, who was later the chief designer of the SAA revolver, obtained a patent for improvements to the Richards Conversion. He simplified the ejector mechanism, and got rid of the frame mounted firing pin, instead reshaping the nose of the hammer into a long, spike like firing pin. This model became known as the Richards-Mason Conversion.
Replicas of this model are currently manufactured by Uberti. Here is a link to the Taylors website showing Richards Mason conversions. Note they are all out of stock at this time:
https://taylorsfirearms.com/hand-gu...evolver/c-mason-revolver-1860-army-model.html
The last of the Colt 'Cartridge Conversion' revolvers is commonly referred to as the Open Top (even though they were all of an open top design).
Replicas of the Open Top are currently manufactured by Uperti. Notice the Open Top lacks the stepped cylinder of the earlier models, and there is a small rear sight mounted to the rear of the barrel.
https://www.uberti-usa.com/army-conversion-navy-conversion-and-open-top-revolvers
Other than my antique Richards Conversion, I do not personally own any modern replicas of the Colt Conversion revolvers. A friend does have a pair of Uberti Open tops chambered for 38 Special and he loves them. He only shoots them with cartridges loaded with Black Powder. They have a loading gate on the side of the frame so they do not need to have the wedge driven out and barrel removed to reload them.
I would recommend that relatively light loads be fired from any replica Colt 'Conversion' revolver. These revolvers have steel frames and are proofed in Italy to standards slightly more stringent than American SAAMI standards, so they should be compatible with modern SAMMI Spec ammunition. But because they lack the top strap that the later Single Action Army revolver had, the frame and barrel connection is clearly not going to be as strong as a revolver with a Top Strap.
Like this:
