Ive been researching this rifle for days and have come up null. I purchased it from a friend who also had no clue of its manufacturer. I would really appreciate any help I can get on this as I'd like to fire it someday, but without knowledge of the caliber I'm afraid that's not possible . Take a look at the photos in the link and see what you think. Thanks!
PS: There is an R stamped on the top of the barrel nearest the bolt (not in the pictures)
PS: There is an R stamped on the top of the barrel nearest the bolt (not in the pictures)