as you know the mosin magazin is made of swaged sheet metal so you have to open the magazin where the case neck is located. anyway the 7,62x54R is enough for anything and will be the last "cheap" surplus ammo for the next time what will be a big benefit. beside of the 308 Winchester its the only other cartridge suitable for the scout rifle concept because of its easy availability.

do you think about something like this?