I was fortunate to get the last russian made 6,5x54R mosin biathlon ammo box. Biathlon today is a girly sport but up to 1977 it was shoot with real rifles. the russians had an own cartridge for this. a 7,62x54R necked down to 6,5mm and an allmost forgotten round today. this is a 20 rounds box made by "188" LVE factory with brass case and a spitzer bullet in 1973. the finish and russian 9,3x53R are very similar and replaceable to each other but the russian 6,5x53R and the finnish 6,3x53R are different rounds. of course it seems possible to load the finnish cartridge into the russian chamber. I measure 6,73mm for the russian bullet and 6,53mm for the finnish bullet. the russian give a V 25 of 745m/sec for the 9,9 gramm bullet and the finnish cartridge is noted with a V25 of 850m/sec for the 2,3 gramm bullet so completly different.