No idea... I have used Pyrodex and APP in my Omega and have had similar results-- even better results with APP. I can not get great groups with 100 grains of it in my gun. 110 grains is the magic amount for me.

I posted a 3/4 inch 3 shot group from 100 yards shot with APP a while ago. It works well for me and I prefer it.

Keep testing. All guns are different.