my Ruger #1S in 45-70 won't shoot plain based lead bullets worth a ****. with gas checked bullets it shoots very good. I got tired of trying to figure out what caused it. one of my favorite loads is 18 grains of Unique with the Remington 300 grain hp and no filler. there is a lot of room for the powder to shift but it doesn't seem to matter. this load chronographs at 1,450 fps and shoots into 1.5 inches or less at 100 yards. a filler with the plain based lead bullet had no affect on the groups. they were always terrible as in 6 inches or more at 100 yards.