Re: Question for 50 Cal shooters
I think you'll just have to try shooting them at very long range and see how they perform. I've shot both 750 and 800 Barnes solids at up to a mile from my 40" McBros single shot but at that range they're both well supersonic.
Computer programs (McGyro and McTrag) can calculate the stability of spinning projectiles and the drag, but they don't calculate the difference in loss of spin and forward energy. They can't really calculate long range stability correctly.
With sufficient initial velocity heavier VLD bullets will typically travel further before going transonic then lighter but faster VLD bullets. It's not obvious which bullet will be more accurate even up to the point where the lighter bullet goes transonic though wind deflection and velocity sensitivity for both can be calculated. Precession effects related to stability are generally too complex to calculate. Really, the only way to know for sure is to do shooting tests at those ranges with various bullets.
Personally I don't attempt to shoot at distances which give transonic velocities. Sure, you can shoot transonic to at least twice as far transonic as supersonic, but the chance of obtaining decent accuracy (limited by wind deflection and muzzle velocity variation) becomes small rapidly after bullets become transonic even it the bullet does remain stable. Time of flight is a big part of both drop and wind deflection. Slow bullets simply cannot compare well for accuracy to supersonic bullets at ranges over a mile whehter they remain stable or not. For subsonic only shooting where the bullet has no stability problems practical hunting ranges can't be over about 600 yards for any known cartridge/bullet combination.. Sure, a heavy subsonic bullet can kill at over a mile, but it cannot be very accurate limited by wind deflection and muzzle velocity variation (usually the latter).
It's practical to build shoulder fired rifles which can reach 2500 yards supersonic. The Cheytacs and similar can do it. They're still too wind sensitive to assure reliable hunting accuracy. 50 BMGs can't do as well. They have too much bore area to case capacity regardless of bullet selection. That is, low drag 50 cal bullets are too slow.