Velocity difference from published pistol velocity to 12 inch barrel 92 results?

[jh45gun]

If the published velocity is listed at 850 fps (roughly 8.5 grains unique) for 45 colt 255 grain cast bullet which is out of a 7.5 inch Ruger barrel what would it be for a 12 inch barrel in a Taurus 92 Ranchhand? For comparison rifle data is 1110 fps for 8.5 grains of unique and same weight cast bullet.

[jh45gun]

Say we round the ruger barrel to 8 to make the math easier so 12 would be in the middle. 1110 minus 850 is 260 so add 130 to 850 for a velocity of 980 that sound about right?

[pirkfan]

I'm guessing the ranch hand will be slightly more than that, because it has no cylinder gap (lost pressure), same reason that pistols get higher velocities than revolvers with similar charges in those little stubby cartridges

[jh45gun]

Ok thanks.