The only long action RAR-Ps that I've heard about were a limited run in 25-06 made in 2016. But even if there isn't a COAL issue in a long action, the 6mm REM doesn't look like a good platform fort the currently popular VLD bullets if the ROT is too slow.
If the shorter case of the 6mm Creedmoor makes it a better fit in short actions than than the 243, going to the longer 6mm REM would seem like a step in the wrong direction.
I'm not anti-6mm REM, as I've had at least one for the past 50 years, but I'm not shooting long VLD bullets in either of mine.
