A secondary problem is that the rifling tends to lead up badly.
This also happens if the shot has a plastic shot cup when the rifling shreds the cup and the lead contacts the bore.
Not surprisingly a rifled barrel has been used to increase the diameter of the shot pattern for close range shooting inside a home.
At typical inside the home ranges the rifling can open the pattern for increased spread, but the penalty is inconsistent spread and possible misses with much of the shot.