CCI Stinger Velocity in 617 4"?

[Magnum 7mm]

I don't have a chronograph and was wondering what the velocity of CCI Stingers would be in A 4" 617 revolver? The published velocity is 1640 fps. I'm sure that's probably from a 22 or 24" rifle barrel.

 

[revolvergeek]

I chrono'ed some out of a Beretta 70s a few years back. It has a 3.5" barrel and I was getting and average velocity of 1245 fps.