Where did you get this powder?, what is the source of supply?
I looked at Accurate Arms page and there are no 9mm loads with AA#9.
Seems to me that someone saw the name "9A" and made the assumption that it has to be "AA#9".
That is an assumption that I don't believe is valid.
Why could it not be AA#5, AA#7, or a bunch of other fast buring pistol ball powders on the market?
Maybe it is Russian, Japanese, Korean, or a Bulgarian surplus powder.You really did not leave a bunch of clues on its origin.
AA#9 is a ball powder, mine has irregular sized grains, but since Accurate Arms buys powders from different vendors, one vendor's ball powder will look different from anothers.