Was that the sound of a gauntlet being thrown down?
Contact me after we get back from Yuma Proving Grounds on the 18th of June with the doppler data on the .408 CheyTac. I may be ready to make a .398 then. It will be every bit a match type bullet, with boat tail, and a BC above .900.
As we are probably the only outfit currently interested in making bullets in that diameter, bullet availability will be a simple matter of calling up and making a purchase. That is until, when and if,it wins some matches. Then I suspect others will get interested.
I do not need to explain the physics to you. Bigger,heavier bullets with the corresponding high BCs will have advantages at long range, especially in wind.
The .408 is a tactical round, in a tactical rifle, with a tactical purpose. The .408 is also not legal for 1000 yd. competition as the rule states that no caliber larger the .40 may be used. A .398 would be legal and it would be an easy neck down from the .408 CheyTac brass. I have not designed it yet, but just for something to mull over, figure a 400 or so grain bullet, .900+ something BC, in front of a case with 145 or so grains of powder capacity. Figure velocities at 3000+ fps. with <30 in barrels. With barrels the length that you use, plus some knowledgeable load development, well who knows. Western Powders and VihtaVuori both have powders in the right burnrate that they have not issued yet. We might even get Federal to break loose with some more 216s let alone some 216Ms. EDM or Gilkes make receivers that would handle it. The Gilkes has a very nice three lug bolt system. A number of high quality barrel makers could make the barrel. Some of the standard rules as to twist and land and groove width and depth will not apply so I could helpful in this area. If everything is done correctly you could end up with a system that starts at Mach 2.5+ is stable and accurate through transonic, to subsonic, and that would have a range that is somewhat further than you are shooting now. Like the .408 is doing to 3500+ yds.
Think of the possibilities. But then this is all conjecture, isn't it?