Very interesting information about the 0.308" bore of the Finnish M-Ns. I have a Finnish Civil Guard (SY) M28 M-N (which has some characteristics of both the M27 and M28), in which I have fired a considerable amount of former ComBloc surplus 7.62 X 54Rmm ammo. Several weeks ago, I got into a discussion on another website with someone who stated the groove diameter of the M28 bore was 0.308", not 0.310", at least those M28s having Swiss SIG barrels, as mine does. Nice to see that verified in print, as I will use 0.308" bullets in reloading from now on. The few M28s I have seen also are covered with a hodgepodge of serial numbers and crossed-out serial numbers (as mine also does), so I guess many were made up out of random parts. I’ve never had any Finnish 7.62 X 54Rmm ammo - does it use the .308" bullet, as I would assume?
By the way - I had a friend (who is well placed enough to know) tell me that M-N rifles are in wide use by shipboard security teams placed aboard some ships sailing in pirate-infested waters, the reason being that they are cheap enough to pitch over the side if a ship enters a port at which small arms are prohibited.