Mostly a lurker here; my focus is Elk hunting. I've read through that thread on RS. My take on this is that it depends on what type of hunting you do, and what your skills are. I hunted with archery for over 20 years, killing over 30 big game animals, and I get the concept of picking your shots, avoiding bone. I met a Wyoming Elk guide that shot a 25-06, but he freely admitted that he was "surgical" about shot placement on a bull Elk.
I shoot both a 264 win mag, and a 300PRC, and have seen how the 300 bucks the wind better than the 264. I love shooting the 264, but when I go on an Elk hunt where I might have a cross-canyon shot at a bull of a lifetime, I bring the 300PRC. I bet that 223 bullet does much worse in wind than my 264. Every Elk guide I have spoken with recommends clients start with a 7mm, and have a preference for the 30s; this is their advise after guiding over 1000 Elk hunts. Sometimes the perfect shot doesn't present itself, or the animal shifts just as you're squeezing off the shot, and you need a bullet that will do the job after hitting heavy bone. In my opinion, a 223 bullet cannot be expected to buck the wind on a cross canyon shot, and do the job after hitting heavy bone.
Cheers
