I’ve had success with my “PB moulds I wished were GC” by using plain base gas checks. They’re a bit more finicky than regular GC but once you get them on they seem to work just as well. You might want to try those – same price as the regular.
Already got a thread going on this a few weeks back, but still eager to play for this very thing, as well as the .316″ version. Assuming they run the same cherry with minor tweaks to the CNC coding?