I haven't chronographed mine, but I've read many gun tests and reviews where chrono results were shown on short barreled guns.
Typically you see data for the 3.5" guns at about 50-60 fps less than a 5" gun.
Like around 775-785 with 230gr ball.
Normally a 5" gun will get 830fps with 230gr.
With a short barreled 45, you'll have to use hollowpoint ammo that is known to open up well at low velocities, or use lighter bullet weights or +P loads to increase the muzzle velocity. Either that, or just accept the performance of ball ammo.
Personally, I use the CorBon 230gr +P loads with the Gold Dots.
This load, when compared against the Speer Gold Dot load, showed that the CorBon was too hot coming out of a 5" pistol, and the Speer Gold Dot load performed better at about 50fps less velocity. So, I figure if I'm getting 50-60fps less velocity out of my short barrel, then the CorBon ought to be just about right in my gun. My gun feeds them just fine.
The other way to go, is to use a 185gr+P load or maybe even the 165gr loads.
Or you could use Hydra Shoks which open up pretty well at lower velocity.
I carry an old MK1 Detonics Combatmaster, and I also have a Colt Officer's Model 45, and a full-size 45.