Like I said, doesn't make much difference to me personally, because my loads don't vary more than 100 fps between the slowest target loads I shoot and the fastest hunting loads. However, I was using the figures Miller provided, which tell us that a difference of 200 fps in MV will result in a difference in lead of over a foot at 40 yards, on a crossing target. And if you take a look at a few pattern sheets, you'll discover quite quickly that a foot is a whole lot of difference--per the examples I gave above, on game birds when your lead changes by that much.
Clay targets aside, if you're used to shooting 1350 fps hunting loads and if you take some fairly long shots, it's probably not a good idea to all of a sudden start using 1150 fps loads--unless you're also going to increase your lead.
As for the famous example that loads with faster MV slow down quicker, and at long range the gap between a fast load and a slow load closes: nope, doesn't happen. The DIFFERENCE IN SPEED lessens, but the fast load continues to "run away" from the slow load. It's just that the fast load isn't gaining as much on the slow one at 40 yards as it is at 10 yards. But the slower load NEVER gains on the faster load. However, the fact that the difference in velocity lessens is important from an energy standpoint: there isn't going to be as much difference in shock at 40 yards between a fast vs a slow load as there is at 10 or 20 yards. If you want to increase retained energy, by far the best way to do that is by increasing pellet size, not increasing velocity. Therefore, the reason "speed kills" isn't due to retained energy, but rather to the fact that if you use the same amount of lead with a fast load vs a slower one, the faster load is much more likely to hit the front end of the bird rather than the back end.
