Interesting, caliber varies from 7.63 to 7.65, so I wonder if it's the actual machined bore diameter or if it's usage on the barrel that actually causes that much difference.
A 7.63mm around .309, 7.65mm, is roughly a .313 bore. Pretty impressive, keeping tabs on barrel wear, kinda like the Swiss and Swedish.
One would think being unissued, or if strongly refurbed, there wouldn't be quite that much variance, but, good 'ol Commie cheapness, run it till it quits
. Kinda makes one wonder, at what point did they rebarrel or do a ground up refurb or did they just simply retire the weapon, in favor of the Ak weapon system..