A PM has a bolt that MUST LINE UP and is grooved to be so, anything out of sinc, is where the problems arise, costly on "O" rings
PM is a straight forward bolt and is so straight forward that the Bolt has been carried through all the DYE Guns up till now,
the last PMR changed the bolt to be the same ( more or less ) so it would go in direct any way you want and Not follow through with a guide,
This alone must tell you that even they must have had second thoughts about the PMR bolt system,
Don`t take my word for it ?? check it out ??
The best in my opinion was the PM 8.= Fantastic gun