It is .57 caliber, 43.5 inches long and has its original cleaning rod.
Jacob Snyder was an enterprising American who came up with an idea for converting muzzle-loading muskets to a new breach-loading system, thus allowing the government to modernize their small arms. Sadly for Mr. Snyder, the U.S. authorities had other plans. The British, however, converted thousands of Crimean and Civil War surplus muskets using his system. The British army was issued Snyders until the adoption of the Martini rifle in the 1870s.
The Snyder continued in use in several other nations. They were cheap and available on the surplus market, and were manufactured from old parts for Egypt, Turkey and India. In North Africa they were even used by insurgent tribes when they could capture them. The Sudanese valued them, as they were the most modern firearm available to them.
Here is an example from the time of the Mahdi's Uprising and Gordon of Kartoum. It is .57 caliber, 43.5 inches long and has its original cleaning rod. I've given it a quick exterior wipe-down. The breach mechanism works fine, though it still retains its old packing grease in the bore and chamber. Some people prefer the old finish but you can easily clean it. Its Arabic markings indicate North or East African use. Aside from the usual minor bumps and dings it is in good, displayable condition. Who knows, it might have been fired at Winston Churchill at Omdurman in 1897. What if it had found its mark. History hinges on such small things.