Rifleman Q&A: Colt 1860 12-Notch Conversion

by
posted on August 20, 2025
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
Colt 1860 12-Notch Conversion
Photos courtesy of Rock Island Auction Company.

Q. At a gun show, I saw a Colt 1860 Army Richards Conversion with 12 cylinder notches instead of the usual six. The dealer was not sure whether this was original to the gun. Were these extra notches a factory variation or just some frontier gunsmith’s backroom project?


A. What you saw was a rarity within a rarity. In 1871, Charles Richards patented a system that enabled Colt to transition from cap-and-ball to self-contained metallic cartridge revolvers utilizing Colt’s surplus Civil War Army parts. A new—albeit short-lived—safety system was devised to prevent the hammer from resting over a loaded chamber.

1860 cylinderPerhaps as an experiment, an extra “safety notch” was cut between each of the 1860’s cylinder bolt notches, making it a 12-notch gun. With the hammer brought to half-cock, the bolt, as before, would drop down into the frame. Then, with the user depressing the trigger while slightly pulling the hammer back before lowering it from half-cock, the bolt would rise up into the safety notch, securing the cylinder with the hammer resting between two loaded chambers.

Unfortunately, the 12-notch system seemed to be doomed from the start. It added to the conversion’s manufacturing costs, and the effectiveness of the safety notches depended upon a perfectly timed gun. Finally, the safety notches were falsely blamed for rupturing cylinders, as, in some instances, a small chunk of metal seemed to be “blown out” from the original cylinder notches.

Some incorrectly theorized that the new safety notches were the culprit. However, those notches were cut between the chambers—the thickest part of the cylinder. Conversely, the guns with “blow-out holes” show them at the bottom of the original cylinder notches, where the cylinders are the thinnest.

Nonetheless, the 12-notch system was discontinued. Of approximately 9,000 1860 Richards Conversions manufactured between 1873 and 1878, fewer than 120 factory 12-notch versions were produced, making them highly sought after today. Beware of fakes, though, as Colt also produced 12-notch cylinders for separate sales and, more recently, unscrupulous individuals have created spurious versions.

Latest

Icarry Taurus TX9 Compact 1
Icarry Taurus TX9 Compact 1

I Carry: Taurus TX9 Compact in a Galco Holster

In our latest "I Carry" segment, we pair the new Taurus TX9 Compact with a leather Stow-N-Go holster from Galco, Inc. This compact, concealed-carry kit is rounded out with an Xolotl automatic knife produced by CRKT.

The Armed Citizen® March 13, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Review: Canik USA MC9 Prime

Canik USA built out its concealed-carry handgun lineup with the MC9 Prime, which is a larger, yet still slim, CCW gun that sits in the same category as other upsized micro-compacts.

U.S. Army Awards Mossberg Contract for Additional 590A1 Pump-Action Shotguns

The U.S. Army has awarded O.F. Mossberg & Sons a contract for approximately $11.6 million dollars to supply the U.S. Army with additional Mossberg 590A1 pump-action shotguns.

250 Years of the U.S. Army: Bolt-Actions & Semi-Automatics on the Battlefield

In just a few decades, the U.S. Army would see itself go from a single-shot, blackpowder design in the form of the Trapdoor Springfield to a modern, semi-automatic fighting rifle in the M1 Garand.

Modernized & Economical Muzzleloaders: The CVA Optima XP & XP-SB

CVA's longest-lasting muzzleloader design, the Optima, has been updated in 2026 with "modern ergonomics and modularity."

Interests



Get the best of American Rifleman delivered to your inbox.