^^^ This parallels my experience perfectly.
My 590A1 with cylinder bore patterns fantastic with low recoil FFC. While with Hornady CD or Varmint Express I can't tell the difference from normal cheap ass Spartan or S&B "bulk buck" loads. The Hornadys react to choke constriction quite like normal buck loads, while the FFC absolutely prefers no constriction at all.
My Benelli Vinci isn't quite as good as the 590 but tracks with it. I was especially disappointed with the Hornady VE #4 buck loads. I was hoping I could get a 50 yard coyote load out of the Versatite wad, but it's a 30 yard load out of that gun at best and even less from the 590. I tried all the way up to full choke in the Vinci and the tighter the choke, the tighter the pattern but past 30 it's just too spread out.
I suspect that the Hornady doesn't perform for these reasons:
- Higher velocity strips the wad from the shot column faster (covers less distance during separation)
- No shot buffer to protect the shot from deformation
I've yet to lay hands on the 1350 FPS FFC load to try but really want to see if it acts like the Hornady at the higher velocity. The jury is still out...