I know that this is 6 months later but I've been using Siraya PET-CF in my P1S with 295 at the nozzle and 80 at the bed. So far it looks pretty good but serious over adhesion of supports on the build plate. Since the parts look pretty good I've stuck with it and use a heat gun to get the supports off with no damage to the plate.
Note: I have only printed a couple of receivers and have not built a rifle yet so I don't know about dimensionally accuracy or fitment yet. When I get them built up I can respond if you're interested.