Posting for a friend. Neat old round, but it is lacking in markings I know how to use to identify it. The bottom date looks like 1807, however that doesn't make any sense. On closer inspection I believe it reads 1897. It's held up very well, so that's a plus at least.
It's about 8-1/2" long with a 2-1/4" width. Not certain of caliber, I wasn't the one doing the measuring.