Here is the PTG reamer drawing link and an opportunity to do a special order on a finishing reamer -
https://www.pacifictoolandgauge.com/338-Snipe-Tac-Finish-Chamber-Reamer_p_118283.html Call and ask for Dave Kiff to see what he recommends for cutting the associated dies (may not be a finisher - but he can get you what is needed.) IF you are starting with a chambered rifle, that's a whole different matter as it may not have been chambered with the listed PTG-spec reamer (not match the reamer drawing and therefore a possible mismatch for cutting the dies) - at which point you are looking at getting a chamber casting and finding a shop that will work from it (preferably that shop doing both the casting and then specing the reamer for PTG, JGS, or Manson). Good luck.