Greetings. One thing i really appreciate about buying high end pencils is that I can swap mechanisms in and out at will (e.g. any p200 mechanism can go into a p200 with tip).
With that being said, I currently own an IJ instruments PG5 (soon to be two) and was wondering if there was a 0.3 mm mechanism that fits into the generic Pentel PG5.
The challenge with PG5 is the lead reservoir is very small diameter, allowing the barrel to have small internal diameter as well. Not too many MPs have such slender internals, so you are fairly limited in options outside of the PG family.
I hadn’t realized it but @amjacobs7 is right about the slim internals of the PG5 being a factor. The next closest 0.3 internals might well be the PMG or PG2003…