Sabots need rifling to work.
Yeppers, I knew that...that's why I shot them, . I did fire a couple throught the smooth bore with cyl (or was it Imp Cyl) just to see what they did.
Foster Slugs shot poor to OK (the OK ones were the 6" - 8" groups) Only Brennekes gave me the 6" - 8" groups without the rifled choke tubes...most others were worse. I guess I tried to keep a long story about trialing slugs short and wasn't clear on what I was doing