James of Hell in a Handbasket spotted this photo on a Peruvian travel blog. It is homemade percussion lock gun. The owner apparently uses homemade gun powder (not hard to do … but kids don’t try this at home).
If you have read this blog for a while, you know how much I like examining homemade guns
Smooth bore or rifled? Probably smoothbore, looks like a pipe for a barrel.
More info about the gun at Hell in a Handbasket.