That was a .22 bird shot. I have one of those sets, thought it would have a high value some day. I have two boxes of targets too. Turns out they cost more than the guns some times. The one I have is a Mossberg, with the "trap" mounted right on the gun barrel. As I recall someone manufactured some kind of thrower to launch Ritz crackers awhile ago and advertised it to be shot with .22 bird shot. Neat idea....

Double guns and English Setters