Pretty tough to give any history with such limited photos and no description. A full length picture and closeup of the lock and trigger(s) plus caliber info would help a lot.
In my opinion, based on what I can see. This is a back lock percussion rifle made by a gunsmith
named Moore, who used a Remington made barrel. Remington started making barrels (1816) long before making complete firearms. As marlinman said more photos would be helpful.
I have some more pics and another gunsmith said it’s a .40 cal. Any information as to what it’s worth would be great! The barrel is 1-1/2”. The flats on the barrel are 1” wide.
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