You will probably have much better results if you don't use over shot cards. Comparing shot shells with overshot cards to those without is like comparing broccoli to peaches.
Grenadier the purpose of this exercise I am trying to get an open pattern from a tightly choked barrel. I'm quite sure that at normal hunting distances of 35 yards or less (I'm not comfortable shooting game over that distance any longer) that there will be no discernable difference betweem rool crimped and folded crim pattern performance so I'll shoot a couple extra patterns with the same load as the roll crimped shells and we shall see.
