I had the same poor accuracyresults earliertoday using Goex FFF in my grandson's new ML. I switched to 777 FFFand the shot groups came right in to the bullseye. Ended up at the 50 yard range using 35 gr. 777 FFF with a 180 gr. 45/50 Speer Gold Dot/Harvester sabot combo. Nice & light for the youngster.
Glad to hear the APP FF worked well for you. With so many powder companies out there now, there's one out there somewhere that brings in those poor shot groups. Sometimes, it's the powder we least expect.