The Colt Single Action Army, a legendary revolver, saw significant evolution throughout its history. One fascinating aspect of this evolution is the Colt Conversion Unit, a fascinating piece of firearms history that allows for the use of cartridges in a revolver originally designed for black powder percussion caps. This conversion often involved modifications to the rear sight, specifically the barrel rear sight. Understanding these modifications is crucial for collectors, enthusiasts, and anyone interested in the history and mechanics of these iconic firearms.
Understanding the Colt Conversion Unit
Before delving into the specifics of barrel rear sights, let's briefly cover the Colt Conversion Unit itself. This ingenious system essentially transformed a percussion cap revolver into a centerfire cartridge revolver. This was achieved through a replacement cylinder, often incorporating a different barrel and sometimes requiring adjustments to the gun's frame. These conversion units were popular, allowing shooters to utilize the more readily available and powerful centerfire cartridges.
The Role of the Barrel Rear Sight in the Conversion
The original Colt Single Action Army revolvers typically featured a simple, often notched, rear sight integrated into the frame of the gun. The conversion to cartridge ammunition often necessitated adjustments to the sighting system. Why? Several factors come into play:
- Different Ballistics: Cartridge ammunition behaves differently than black powder rounds. The trajectory and point of impact are altered, demanding a sight adjustment for accurate shooting.
- Barrel Modifications: The conversion units sometimes involved a modified or replacement barrel. This new barrel may have a different sight profile or require a new rear sight entirely. This is where the barrel rear sight becomes crucial to the accuracy of the converted firearm.
- Improved Accuracy: The conversion process, including sight adjustments, aimed to improve the accuracy of the revolver when firing cartridges.
Types of Barrel Rear Sights Found on Colt Conversion Units
Several types of barrel rear sights were employed on Colt Conversion Unit revolvers, depending on the manufacturer and the specific conversion kit. These include:
1. Simple Notch Sights:
These were often a simple continuation of the existing frame-mounted sight, potentially adjusted for height or width on the barrel itself. This was a cost-effective solution but offered less precise sighting capabilities.
2. Adjustable Sights:
More advanced conversions sometimes incorporated adjustable rear sights, allowing for finer adjustments to elevation and windage. These usually featured a screw mechanism for precise adjustments. The position of these adjustable sights (on the barrel or frame) varied.
3. Specialty Sights:
Some custom conversions or later production units might incorporate unique or specialized rear sights. These are less common and may bear the markings of the gunsmith or modification shop that installed them.
Identifying Your Barrel Rear Sight
Properly identifying the barrel rear sight on your Colt Conversion Unit revolver requires careful observation and potentially some research. Look for:
- Markings: Manufacturers' markings or other identifying information might be present on the sight itself.
- Construction: The material (steel, brass, etc.) and the method of construction can offer clues about the sight's origin and age.
- Adjustability: The presence or absence of adjustment screws indicates the sight's level of sophistication.
Maintaining and Preserving the Barrel Rear Sight
Proper care and maintenance of the barrel rear sight are essential to preserve the historical value and shooting accuracy of your Colt Conversion Unit revolver. Avoid using harsh chemicals, and regularly inspect the sight for any damage or wear. If cleaning or repair is needed, consult a qualified gunsmith specializing in antique firearms.
This detailed exploration of barrel rear sights on Colt Conversion Units provides a comprehensive understanding of their significance in the history and functionality of these fascinating firearms. Remember, always handle firearms safely and responsibly.
