If it is low pressure you value most, move away from the AA hull and move to a larger volume hull, i.e. Federal Gold Medal.

If it is making the best out of the AA Hull then hit the Hodgdon site or Alliant site as JDW described, there are options thre.

While I do not believe it a great extreme cold weather powder I have found SR7625 a good low pressure powder in a Gold Medal Hull.

Michael Dittamo
Topeka, KS