I’ve have/had a 6.5prc in all 3 sizes SA,XM,LA.
I will say setting it up in the long action was aggravating trying to get it to feed properly. Once you have it dialed in it worked like a dream. Berger 156EOL set long was/is my bullet of choice
On the short action it work smoothly with factory loads, but I ran out of room for my reloads.
My defiance XM (nitrated) has been a dream. When I ordered it I bought 2 bolts 308, and magnum bolt face. I run it as a switch barrel with the 6.5 PRC and a 6.5 Remington with plans of spinning up a 7 something. All of those cartridges like the bullets set long (for me anyways). I went with Hawkins bottom metal and MDT mags.
This is just my experience, and I hope this helps you out.