In the past when I loaded 165 SSTs in RP brass for a friend I used 46 grains of Varget and the CCI 200. This clocked in the 2740 range out of the 24" barrel of his Kimber Longmaster.

If I remember the Hornady match brass weight correctly it's about the same as the old RP around 167 grains, so the capacities should be similar.

Back up from that a bit and see if you can work up to your window.

Have you pulled any bullets and examined the powder in a factory round?