I love
Rory, and I used to think it needed a 'longer' name but I definitely feel it can stand on its own. I don't really see it as a natural nn for
Richard (which isn't my favorite name in general; it's just dull to me) but I don't see why not. But if you don't love
Richard, I wouldn't suggest using it as a full name because you feel
Rory should be a nn. If nothing else, I think
Rordan is the best name in which
Rory could be a nn, but like I said before, just plain
Rory is better. :)