I really do wonder why,i had a Lyons & Lyons Invisible Paradox Shotgun,it was a Sidelock SxS,was bought in 1950s, basically a Trade Gun,whatever little info i could get it was built for Army Navy, used to gimme very good groups shooting Slugs till 50 yards, excellent shooting Shot from 7.5 to LGs. Regarding shooting slugs out of a Choke barrel,Slugs here are 85% Lead and 15% Antimony,the German - Spanish one we shot also the same.Overusing Slugs might hurt Extra Full or Turkey Choke Barrel,but the ones with Half Choke, would it????