 In practice, steel shot patterns as much as two chokes tighter for a given amount of constriction.In other words, a choke that patterns "Modified" with lead or bismuth shot would give a "Full" pattern with steel shot.To avoid excessive wear or grooving from occurring within chokes when shooting steel shot, many manufacturers recommend avoiding shooting steel shot in any chokes marked tighter than "Modified", unless the choke tube is specifically marked as being safe for use with steel shot.