Marine, I have a 5" and an 8 3/8. If you want I will chrono each. Do you want to know about factory Hornady or my pet hand loads or both?
Will this even help you? I will tell you this right off...in MY two guns SOMETIMES the lower power loads go faster out the 5". But they don't shoot as well....SOMETIMES. Both guns want slightly different loads for the BEST accuracy.
The wife's loads that she keeps in her 5" are 250 grains at about 950 fps. These run 815 in my XVR...go figure.
Now, the real problem is the blast....after 800-900 fps with any powder you'd best not have to shoot it with out muffs.
At the power level/velocity of the 460 I personally think the velocity loss or gain is a non issue, but I'll be happy to generate you some hard numbers with my 5 an 8 if it will help you.
HD2