Not True! The "rifling" on a Foster style slug does not impart any spin! The Foster slug works on the "rock in a sock" theory for stabilization, the same way a badminton shuttlecock works. The nose is heavier than the tail, which never allows the tail to catch up and cause it to tumble. That is why Foster style slugs are hollow. I have put about 250 Foster style slugs through my fully rifled Remington factory barrel and it still shoots as good as the day i first took it out of the box. As stated previously though, lead fouling is a problem with them, so use a good lead remover and you will be fine. Like a few of the others i never shoot past about 60 yards or so with them as the accuracy goes away fast on them. On the other hand, at about .720 inches, these big old slugs are devastating at short range. They kill like the Hammer of Thor!