I have a Samuel Forker, born in Brownsville, PA November25, 1798. Moved to Meadville, PA in 1823, mentioned in the Daily Pittsburgh Gazette, March 9, 1837. He is credited with inventing a firearm where "four loads can be discharged in rapid succession from a single piece". He was the son of Adam Forker, a blacksmith from New Jersey. Samuel had a brother, John who was also a gunsmith who settled in Mercer Co., PA in 1816. He had a son named Joseph who was a gunsmith for a limited number of years. Samuel had a son named William H., born in 1828 who was also a gunsmith. He was still living in Meadville in 1899. Samuel died in 1860. So you can figure your rifle was made before 1860.