The lead shot won't damage the rifling - but, other than the dimensional issues between the two cases, rifled barrels tend to really donut shot patterns. One of the local law enforcement agencies bought a fully rifled deer barrel for slug shooting. But they also have to qualify with buckshot. Couldn't hit the target at 25 yards with 00 Buck. The area a couple of feet outside the target, on all sides, was pretty well shot up - but nothing in the middle.