I'd say stick with what has worked, but do not close the door to trying other loads. I switched a few years back to a shot shell that grouped better in mine. I had used the same stuff for probably 20 years or so. I only tried 3 different loads (Federal, Winchester, Remington) , so the "test" cost was not all that bad.

Some of the e can get really costly ... like my buddy's 12 ga, Nitro 3 1/2" stuff. He brought in a target yesterday that was amazing. At a measured 40 yards, using a Benelli Nova and a .660 choke, he had 128 pellets inside a 10" circle in an almost perfect circular pattern. I wonder what it'd look like at 15! Like a rifle shot ..... 3" across !?! Not bad at all at 40 yards, wow ! But this shell costs about $7/round so it had better be darn good stuff!