I don't own either. There. I said it. But I do keep a keen eye out for modern developments and my next rifle, whenever that may be.
For whatever reason, the 6.5 caliber is hot. Best I can tell, it's one of the best compromises between killing power and recoil. That's one good thing.
And bullet manufacturers are, at this time in history, giving us all a lot of good choices. So are makers of loaded ammo. That's two.
And all these technological improvements seem to be heading towards "Given modern bullet design and modern powders, you don't need as fat a bullet as your Dad and Granddad used to in order to inflict the same damage."
So. In this modern, updated, world...
same damage, less recoil.
Or, same damage, less drop/wind drift.
Ot, more damage, same recoil
So, your two 6.5 mm choices here are both excellent.
If you need to find ammo in every town at any time and can't afford to lay in a few hundred rounds ahead of time until the next opportunity to buy, I'd go with the CM. It might also be a little cheaper per round.
For the external ballistics, I'd way, WAY, prefer the PRC.
Today, pandemic and all, it's as simple as going to Midway to order ammo And have it delivered to your door. It is in stock as I write now. But if you are going on an African safari and might need to be able to acquire rounds overseas, there are better choices than either.
And if you don't want to put up with much recoil, and there's no shame, nay, advantages in that; then go for the CM and be happy.
Both seem like great cartridges to me. The CM was designed for short actions and low recoil. The PRC won't fit in a short action but will deliver more velocity and more powerful external ballistics, at the price of a little more recoil and a SLIGHTLY heavier rifle ( which will SLIGHTLY tame that extra recoil). Given this understanding, me, I'd lean towards the PRC. Your mileage may vary.
If you haven't joined the Bergara Groups on FaceBook, do so. There are a lot of supporters on there and it will take a lot of reading on your part. Bergara's are a very nice rifle but their QC runs hot and cold. There may be better options out there that you will be happy with.
I didn't even think about looking online for a group. I figured Facebook kicked them all. Thanks for the idea!