WHAT'S the pitch?5/16 x 14 but different pitch to thread . brass insert do not accept the later model threads . the pin in butt will accept either .
Exactly. Just same 5/16x14 with major about 0.300 or 7.65 mm outer (major) diameter. You could use 5/16x14 shaft on Schon cue, not Schon shaft on 5/16x14 butt.5/16-14 with a major diameter of a little over .300 and not full .312 inches.