That's a lot of words to say drag increases exponentially with increase velocity.
Nope, not the point, which is this: We all (I think) understand that faster loads slow down quicker than slower loads. However, some people interpret that to mean that, at some point, the slower load will start "catching up" to the faster load. Wrong. The faster load will always have a velocity advantage over the slower load, and will thus--if they leave two barrels at the same time--continue to stretch out its lead over the slower load. It's just that it won't have as great an advantage (in velocity) at 40 yards as it does at 20 yards.
Re difference in forward allowance . . . I hate to do the math, but I did once, if I recall correctly, using the example of a crossing pheasant at 40 yards, flying 50 mph. I believe the loads I used were 1400 fps vs 1220 fps. The difference in forward allowance, as I recall, was 9". Assuming you center the rooster with the fast load, you'd probably still hit him with the slow load--but it'd likely be a crippling vs a killing hit. And if you're talking smaller targets (like a clay or a quail or a dove), could very easily be the difference between a hit and a miss.
Note, however, that's a fairly extreme example: crossing target, fairly long range, pretty fast, and a significant difference in MV between fast and slow loads.
Last edited by L. Brown; 03/22/12 09:47 AM.
