I've been watching the px for a while now hoping to find a Carbon Fiber Bartlein 6cm blank or Terminus pre fit but they just don't come around much. For whatever reason , the 6gt barrels come up somewhat regular but that's about it for 6mm. I have a price to order one from SPR and a price on a Bemchmark CF but I'm having a hard time pulling the trigger and not going with Bartlein. Good luck, if I see one I will send you a link