Found MUSKET in thrift store.

[Claven2]

I wouldn't assume the rifling is bad. 19th century rifling, especially pre-1870, was not that unifiorm. It may have been made the way you see it - generally these were not shot enough to wear rifling out. Also, the original rifle round in a Jager would have been patched ball, so the rifling just grabs cloth, not the bullet itself. I wouldn;t sentence it as a non-shooter unless I had tested it for safety and then accuracy.

Cheers.