Elsinox Oh, okay, interesting. So this doesn’t have rifling then. Those little triangular cutouts are only on what is called the crown. I suspect they were intended to serve some other purpose. As the projectile leaves the barrel, gas will escape differently than it would from a simple cylinder that extends all the way to the muzzle. It may help with projectile stability as it exits the barrel, or perhaps it was intended to assist with loading. Who knows.
The other marks are simply turning marks from the manufacturing process. The fact that they are still visible points to a relatively unrefined machining process, which is consistent with 19th century production. This most definitely is not rifling.
At first glance, the smooth bore suggests a mid-19th century firearm. The use of a percussion cap narrows the timeframe further, likely to somewhere between about 1820 and 1850 based on the features present. Of course, it is worth keeping in mind that it may have been built this way simply because of the tools and technological limitations available to the maker. It could potentially be a later build that retained older design characteristics.
The absence of a firing pin and receiver also points toward a mid-19th century design or earlier. This appears to be a muzzleloader, loaded from the barrel end. If it were significantly newer, I would expect a completely different design, likely using a period rimfire cartridge (not a modern small-caliber rimfire) along with a break-open action, receiver, and simple firing pin.
Very interesting @Elsinox. Thank you for sharing it.
