There's no real magic powder that does better in the Striker (or other short barreled firearms). I would look at powders that are in the normal burn range for the 243.

IMHO the best do it all powder for the 243 is Varget. It works terrific with the 55-87gr bullets and works well with the heavier stuff. For the 95gr and up stuff RL19 and RL22 can be good substitutes. I have run several 243 and 243AI barrels in short and long lengths, and that is the best advice I can give on what has universally worked well for me.