I have had the impression that the primary reason for the 6.5 CM's existence was to be a better vehicle for launching longer/heavier VLD bullets in short action rifles.

If you're going to reload and higher velocity is an important consideration, why not just go with a case that has more capacity, like the 6.5-284 or 6.5-06 or a variety of other options that are available to folks who load their own?