Don't mess around here!
A "12 pound" M1857 Napoleon cannon. It is of a French style, named after Napoleon III in 1857. This is a "gun." A "rifle," you carry. It has a smooth bore, not rifled. Reliable, safe, and good at killing. This gun can throw solid or explosive ball ammo weighing 12 pounds a Thousand Seven Hundred Yards, and throw canister, or grape-shot, to 300 Yards.
You best stay away from the front end. Confederate Napoleon models usually had a straight barrel at the muzzle; Union Napoleons had a flare at the muzzle, called a "muzzle swell." That's enough knowledge for now. Stay tuned.