Ok, I dug 2 out, an early refurb '50 Russian and a '58 Romanian.. the rest are buried including my '52 laminate Russian..
Figured no one else wanted to rip one apart
Look at the gap between the crossbolt and receiver.. This is all Russian fitting, Russian stock and receiver, some warpage probably wouldn't affect it much, it has room.....ample room for movement
now.. just wait for it......
This is the same Russian stock shown above fitted on a '58 Romanian, very snug fit, but it fits great, notice no gap..
Maybe its not a crossbolt issue, maybe it's the mount area on the barrel/receiver, or lack of on early rifles... this is the crossbolts mount on both rifles.. notice the Russian, very small and narrow vs. the Romanian large and wide mount, a lot more surface area. Even the flange on the barrel is noticeably thinner, almost half the thickness on the Russian.
So I'm not biased to Romanians...Here are 3 Romanians and a 9 million /26\ Chinese(far right), all are wide vs. the above '50 Russian
A late '50's Soviet built.........Soviet Sino, again a wide mount and thick barrel flange.
Maybe..............there are 2 variations, maybe 3, early and late and maybe a universal fit all stock, like non chrome/chrome bores and all that jazz, there is a visible difference in where the crossbolt sits, on an early rifle there is not much tolerance vs. later rifles. Early rifles would have had less room for error on the crossbolt vs. later rifles with that wide flat, and a universal stock would be the best of both worlds.
I can not imagine the receivers being different, both of the ones I have measured the same from the rear to the flange where the barrel mates.