B & P, Fiocchi, Hull, Eley & Kent/Gamebore competition loads are among some of the best in the world... domestically, Federal Gold Medal paper's are certainly big favourites, as are the Remington STS/Nitros. The "AA-s" just ain't what they used to be.
In the present batch of AAs I have noticed two different hull lenghts. One is about 1/16 shorter and crimps differently. I do not mind sorting hulls by color, but with the minute advantage to loading, sorting by measurement seems a pain. Just means that not all my crimps might be tight and I end up with some shot in my pocket