Don't think they could get around the rifling issue due to ATF restrictions.
I can tell you that I had much better luck achieving a good shot spread at 20 yards with an older .45LC/.410 octagon barrel than I had with any of the conventional vent rib barrels I had.
Not sure if it's the difference in the type of "choke" each barrel uses or something else.
There's also a YouTube video floating around where someone used a 10' VR barrel with success. Talked about the loads and showed the groups he was getting prior to the actual hunt.
Good luck in your search and hunting.
John