There are infinite (or nearly so) possibilities for mounting a scope on a Handi!
One option I've chosen is to replace the factory base with a harder-steel Ironsighter that has picatinny type grooves across the top. (from MidwayUSA.com)
The rings I use are the Leupold all-steel (PRS or PWS or similar lettering) that allow for fairly quick on-and-off of one Handi-Rifle to another! (once a scope is mounted and rings tightened, if the same base is used on more than one rifle, the scope-ring [unit] should switch to rifle to rifle to rifle WITH NO PROBLEMS, except sighting in each time.
Since I cannot YET afford all the scopes I need, that is the route I've gone. Those NEF Ironsighter bases also lend themselves well to being modified with bigger screw holes when tapped with 8-40's vs 6-48's that come on the Handi.