It depends on the powder used to propel the bullet.
There is no way of knowing the velocity of a given load without running it over the chronograph, especially if you're trying to know what a single load is doing when fired from a revolver vs a carbine.
For example, I've got one .357 magnum load that gives me 1300 fps from my revolver and 1600 fps from my carbine. This load features a 180 grain gas-checked bullet and Hodgdon L'il Gun powder. It's a great load and when you touch it off, you know you've got a magnum in your hand. That 300 fps difference between the handgun and the carbine is actual measurement, shot across my chronograph.
On the other hand, I've got a target load that features a small charge of Bullseye powder and a 148 wadcutter bullet. It gives me 680 fps from my handgun. When I ran that load through my carbine, I found that I was only getting 606 fps from the 16" barrel. I speculate that the small charge of fast powder was running out of pressure in that 16" barrel and the bullet was slowing from friction. I stopped running that load through the carbine. I don't want a bullet stuck in the barrel by accident.
Short answer: Unless you run it over a chronograph, you don't know.