My searching shows some (very few) fairly high velocity loads, around 1400 FPS; but these are not from companies, they are from inidviduals. I've also found a number of powders that the fastest loads listed are around 1000 FPS, these are in my books and official websites.
I'm wanting to go to 1300 FPS, I guess I could work up to it and see what happens. All I've ever shot over 1000 FPS out of my Blackhawk is jacketed hollowpoints.