I posted earlier about exercising caution with hot loads, but to me the frame material is not a particular concern. I am thinking more about the overall construction of the gun. If a polymer framed 9mm is built on a frame that is also used for .40 S&W and .357 SIG, then I would not be too concerned about the strength of the frame. The Ruger PCC is a blowback action. I don't have time to research the recommended ammo for the PCC right now, but in general blowback actions are much less suitable for hot rounds than locked breech actions. I would not feed any blowback action +P+ ammo unless I was certain the action was heavy enough for it.