410 is a shotgun, not a rifle. And I can't find any H&R Model 1915, rifle, shotgun, or pistol, so that is probably a patent date. What type action does it have and are there any other markings?
The 410 Handy Gun is a pistol which fires 410 shotgun rounds. It is impossible to register and illegal from what I've been able to gather.
The Handy Gun is a .410 bore shotgun pistol manufactured by H&R. The Model 1915 was the successor to the Model 1905 shotgun line. The 410-12mm refers to the bore size simply in millimeters instead of inches. They were also marked 410-44 from 1916-1921. The 410-12mm marking was used between 1922-1936. If the gun is not already registered as a short barreled shotgun it will probably not be allowed and will most likely be confiscated by the BATF.
I have a standard Model 1915 myself.