Good article, and I too agree on the 6mm/257 as the functional baseline for Texas Whitetail.
I've seen a few folks shoot deer with .223s and the like, and while it's technically killed them just as dead, the margin for error is much greater. On a related note, I've also come across a living deer with 2/3rd it's skull missing while out varmint hunting at night (deer was standing in a creek that was 2-3 ft deep and completely unresponsive to my presence) ; I always just assumed it was shot with a smaller caliber that deflected off hard bone. It was a sad sight.
Bottom line, if you're going after hogs and bigger deer, it's probably a good idea to leave the .224 based calibers in the gun safe. IMO a 260 Rem (or other 6.5 calibers) is just about the ideal Texas whitetail deer cartridge. (Highest SDs, close to the highest BC with 140grs, lethal out to even the longest hunting distances, and relatively low recoil). What's not to love about that?!?
Regardless of if you're hunting with a .204 Ruger or a .505 Gibbs, the most important thing is knowing how your rifle and scope will perform at varying ranges/conditions. If you have quality equipment, and know how to use it correctly, anything inside 300 yards should be sitting on your dinner table that evening.
Take Care.