Blue Dot is a close second. AA9, AA7, and Power Pistol also work well.
That's a dangerous place to be. When velocity stops increasing in proportion to charge weight increases it doesn't mean that the pressure doesn't continue to rise. What you see is a very small or neglible in crease in velocity for more powder and then the time/pressure curve goes straight up and stuff goes everywhere.The powder is weird in that after a certain level is reached adding more powder to the load actually reduces velocities much like I've seen with Lil Gun in the Casull and Linebaughs.