Clearing this up once and for all AA have their pellets produced at the JSB factory to the JSB 7.87 specification and shape but use 2 brand new dies and quality control the pellets post die.
They come out of the Die with a slightly different finish but this was not intentional.
The AA is therefore a better pellet costing more money due to the hand sifting.
The reason the AA is performing less well when quickly switching from the regular diet of JSB is probably psychological, finding little or no improvement over the JSB but costing more .
Potentially they have the edge but so close it might be more down to how your shooting on the day or the effects of wind.