Mr. Brown,
Yes, but. The important factor here is the shot size.
As you said, the retained energy of big shot is much greater than that of small shot. Also, big shot carries its speed much better. Its mass overcomes the friction of the air and the gravety much better than the small shot.
It is the 71/2 and even the 6s (in hunting)that get the great reduction in speed in the fast vs. the slower loads tests. A high velocity 4 hits damn hard way out there. If you use 71/2 or even 6s a big pheasant will almost shrug it off at 70 yards. With 4s you will kill it dead.
All the, as you put it, "famous example[s]that loads with faster MV slow down quicker" with the conclusion that the force is nearly the same at distance that I am aware of have used 71/2 shot or even 8s in their tests.
The big stuff carries its momentum.
Jake
