I am a proponent of the 5.56 for accurized rifles, but it has some limitations. Here’s a single datapoint to consider: A friend and I were shooting steel at 800 meters in a stiff wind. My friend was shooting 6.5, I 5.56. The Creedmore shooter had to hold off 3 feet to account for wind. I had to hold off 10 feet with my 5.56.
Food for thought when considering the merits and limitations of 5.56 precision shooting.