VarmintGuy,
Extend your ballistic tables to 500 yards and you'll find there's no difference in "flatness", but even more difference in wind-drift. I usually use my .204 at ranges from 300 yards to around 450-500, depending on the wind, and yes, there is a definite advantage to 40's.
At closer ranges I use much smaller rounds, these days usually one of the Hornet-based rounds, from the .17 Hornady to the .22 K-Hornet. But even when I've used the .204 for ALL prairie dog shooting, I much preferred 40's at ranges beyond 300, because of wind-drift. (Beyond 500 even more wind-resistant cartridges and, especially, bullets help considerably.)
Yeah, if the wind is STEADY holding off isn't a big deal. But in my experience it rarely is, and a bullet that resists wind more also reduces variations in drift due to variations in wind velocity and angle. If you actually tried 40's much at 300+ yards you'd realize this. It's not theoretical, but quite obvious to anybody who actually tries it. It was to me the first year the .204 appeared.
