Early 1970's when I got bored w/ shooting modern competition trap , bought a 12 ga. and 10 ga. Pedersoli sbs double. Had a quantity of modern shotshell components left over from reloading thousands of modern trap shells , so just started experimenting , and using the modern wads in the Pedersoli 12 ga. Far as I could see , most every wad worked well , except for one brand. Still remember this failure......Put up a patterning target to test some George Leonard Herter , World Famous shotgun wads. I laugh.....At the 20 yd. target patterning paper , the wad and shot made a perfect key hole , with no shot pattern. I still laugh out loud. , My immediate reaction was , from knowing almost nothing about this subject , was , "could this be used to kill a deer? I'de just never experienced anything like that. l However , learned something from this event. Don't use any of the old school , thicker plastic wads , as the initial pressure spike in a modern shot shell would be high and abrupt enough to cause the old type plastic wads to open on firing , whereas black powder builds pressure more slowly. My favorite wads turned out to be the thin winged plastic wads from Balistic Products. This wad could be used in any smooth bore from 14 ga. , to 10 ga.. Don't know why , but never had problems w/ plastic buildup. Also , never used any plastic wads in m/l shotgun competition shooting just hunting.