I posted a similar topic a year back in shooting a 1oz load of 7.5 shot. I thought I gave away or sold off the shells I inherited, but to my surprise I have another 3/4 flat missing two boxes.
So to be honest, I am very skeptical in even trying a box. The shells are the white box Winchester AA shells. I have shot nothing but 3/4oz loads through both my 28s.
Has anyone ran the extra 1/4 oz through there 28s?