You have a shell-holder design rifle built by Robert W Hart & Son Co. If you call Robert W Hart & Son with the serial number on your rifle, they will be able to answer any questions you may have about it. If you cannot find the serial number, they will be able to lead you to it.
Robert W Hart & Son has been in the accuracy and long-range rifle business for many years. They are not affiliated with Hart Barrels AFAIK (there may be a family tie or not). Hart barrels is in Lafayette, NY and Robert W Hart & Son is in Nescopeck, PA.
Contact info:
Headquarters
401 Montgomery St.
Nescopeck Pa, 18635
Office: (570) 752-3655
Order Line: 1-800-368-3656
Email:
[email protected]
Because of the fluted barrel, my bet is that your rifle is about 10-15 years old at most.