Sure it is reasonable, you are just going to have to get them right in your face. Depending on your constriction (which is hopefully at least 1/2 choke) I'd say that much beyond 30 yards may be a touch risky, and boarder line irresponsible. Certainly going to need to take it out to the range and put it through the paces and find out what sort of range you'll have a good pattern at.

What gun are you shooting? I'm a double gun buff by profession (although I get to do very little true double gun stuff anymore)... always interested in this sort of thing.