I received this underhammer rifle from a family member, but I can't identify it. It has a tag that says Allen 50 caliber,but it has no markings. It is a buggy rifle, the barrel is 16" and the overall length is 30". Thank you.
Dang, looks like the top portion is a "site" and the percussion hammer is forward of the trigger guard below the barrel. I did find a Video of a 45 caliber Hopkins & Allen Underhammer that is similar to yours. You might browse links to a number of similar firearms.
I believe it to be an early Allen. Allen started making guns (pistols), early 1800, but didn't start adding (contracting) other names until later. Is the barrel rifled? Some of the Allens had smooth bores. Just my thoughts? I have a 1905 Hopkins & Allen 12 ga shotgun that my Grandfather paid $7 for new. MY 10yr old great grandson shoots with it at turkey shoots. I also have a Page & Allen ( My name is page) Olympic rifle.
It looks rather unlike any Allen underhammer rifle I have ever seen. The shape of the hammer and the straight trigger are unlike the Allen underhammer "pocket rifle", but they are both quite like the shapes used by David Hilliard of Cornish, New Hampshire. If you do an image search for "David Hilliard underhammer" and "Allen pocket rifle" you will see what I mean.