I thought you could go as short as 16-1/2"?? And still be classified as a rifle?? Any good gunsmith would know.
I think it is a good idea if you are a woods hunter. You will probably burn a little less powder. But I don't think you would be giving up too much. Or at least not enough that it would make any difference in woods hunting distances.
I like a shorter rifle. That is one reason I like the Encore. They are 3" or 4" shorter to start with since there is no action.
Take a look for one of the Katahdin MZ barrels. I don't remember how long they are. But they are shorter. Tom.