Yes, any 20 gauge H&R can easily and safely be drilled and tapped for a scope rail by any competent gunsmith, and even by many of us shade tree mechanics with a drill press. I have two 12 gauge Tracker II's that have beed drilled and tapped and which have had scope rails screwed and epoxied on. It IS doable with a newer 12 gauge barrel (the older ones were thinnner and probably not douable) but it is painstaking work only to be tried by a good gunsmith. My first one was drilled for 8/40 screws instead of the usual 6/48's, tapped to the bottom of the short hole with a bottoming tap, the screws were each fitted for complete and proper fit to the tapped hole they were going in. The holes in the H&R scope rail was redone by the smith to fit the 8/40 screws correctly and then the rail was set with epoxy and the screws. It is safe and secure. It can be done to a 12 gauge, but not easily or cheaply. Drilling and tapping a 20 gauge barrel is childs play compared to a 12 gauge...<><....
