I know what you mean about the heat... been tryin to mow our place on weekends and with no top it gets pretty danged toasty sittin atop tha tractor. About 10am it starts getting annoying and by noon almost too much.
That is a nice shooting load. What did you end up with?
I'm using up some surplus powder I picked up a while back that is sorta in between AA9 and 296/110. With a top end load out of my Redhawk, I get just over 1400fps form those cast pictured above, and right at 1500 with the Remington bullet. I haven't loaded up more than enough for testing for velocities and leading. It was a short session at the range.
I can say this, that old Remington 200gr SJHP has been the demise of a bunch of hogs and a few deer. It shoots flat enough between 1350 and 1500fps that you don't hold off hair out to 100yds or more. Even at the longer ranges it plowed right on through.