BillinOregon mentioned tweaking the frame so you couldn't interchange rifle and pistol parts...
Only problem, is I don't really like the H&R looks. Sure, some of them look sort-of neat, and I love my 45-120 for the combination of price and power, but they would really need to get a good looking pistol grip going for me to be interested. IMO, TC's look much better than H&Rs, but they are also much more expensive, and have the same accuracy issues. I think H&R could make their guns look just as good by changing stock and forearm design.