There are several good powders that work well in this beautifully designed cartridge. I've used Rel-19, H-4350 and have work up shells with Rel-22 and 140gr Rem, Hornady, and Prvi-Partizan 139gr SP waiting for good weather. I have some shells loaded with H414 behind Hornady 100gr to try also. I'm hoping the lighter bullets perform well in the 1in9 twist.
I have some H4831SC waiting to try with the heavier bullets too.
AA3100 looks like it has potential on paper.
I can't test this weekend because of a trip to Commerce, GA that's upcoming. Things will be warming soon and I'll be able to chrono and check groups.
NCsmitty