Couple of us have talked about getting a tightly choked gun, and rifling the chokes just to see what happens - best laid plans of mice and men! Maybe one of these days.
Trouble is, we'll need a full choked 16 or 12 with only 24" to 26" bls. to start with, having a full 40 points of choke per barrel- or to rifle the full choke and leave the modified tube (if so equipped) smooth. 28" to 30" is getting a bit long in the tooth for me.

I've lots of slower twist barrels to use for rifling rod guides.