Don't forget the other reason for 6.5x50sr was the fact the Russians bought a ton of Type 30 Arisakas from Japan during WWI to try and make up for the lack of rifles they had (spoiler it didn't make up the numbers required).
Don't forget the other reason for 6.5x50sr was the fact the Russians bought a ton of Type 30 Arisakas from Japan during WWI to try and make up for the lack of rifles they had (spoiler it didn't make up the numbers required).