Your rifle appears to be from New York, based on several details: a single trigger [most rifles made farther west had double-set triggers], smaller-than-average rear spur on the guard, shorter-than-normal forestock length out to rear ramrod pipe, longer-than-normal cheekpiece with heavy incised line and almost no defined forward end toward the wrist, and somewhat odd inlays in cheek and forestock such as the star with many long, skinny points... all typical details of a New York rifle. If this 1845-1850 rifle had double keys in the forestock, many collectors would call it a "plains rifle," but being from the East, it has only a single key and would be called a half-stocked hunting rifle. Its large bore makes it incorrect to call it a "squirrel rifle" as many small caliber rifles were called during the same era.
The heavy bore was probably made for either:
1) hunting large animals in New York's northeastern Adirondack or Catskill Mountain, where large game [moose, deer, bear, etc.] were still plentiful, or
2) someone heading west where they may encounter uncertain or dangerous circumstances in the mid-1800s.
As mentioned, the lock is not the original one, but the gun has always been percussion based on its mid-century style and single lock bolt. The barrel seems a little short and may have been shortened a couple inches at one time, a common practice on percussion rifles when the percussion cap fulminates began eroding the barrel wall around the side lug. Heavily used rifles were often shortened several times during their working years, losing about 3/4" to 1"of barrel each time at the breech end. But without a hands-on inspection, it can't be determined if actually shortened, and if so, by how much.
The curly maple stock suggests the gun was probably made well outside of New York's major cities where walnut stocks were preferred. Every smaller town also had its gunsmith, an essential tradesman of the day, but without initials or a name on the barrel behind the rear sight, the gun's actual origin will probably never be known.
Shelby Gallien