What would you recommend for a 6.5 PRC?
For a 1.5in diameter can the TBAC Ultra 7 or 9 are as good as it gets but if you don't mind a can that is a little larger in diameter the Dead Air Nomad Ti XC which is the newest version of the Nomad Ti, for its size, is crazy quiet. I recently got their new Nomad LTi XC which is a little longer then the Ti XC and they are one seriously impressive can. I put a direct thread end on my LTi XC and that dropped a few ounces off of it over using their HUB and Xeno setup and I think it is slightly quieter with the direct thread.
In the big suppressor shootout TBAC did with as many different suppressors as they could get their hands on, which was a lot, the new Nomad Ti XC metered the same as the Ultra 9 did but is over two inches shorter and .25 larger diameter.