the fun fact is acctually most of NLF and vietcong soldiers in the south don't use much mosin nagant rifle . those rifles mostly in the Rear Echelon troops ,militia , arms worker hand staying in the north vietnam . in the south most of vietcong fighter in early war using left over mas 36 and arisaka rifle (not much), m1 garand , m1 carbine (many) left over from french rather than mosin-nagant because early war 7.62x54R ammo for mosin are much less available in the south than ammo for mas 36 , american m1 or arisaka
in the year of 1960 > 1965 mainly issue rifle for NLF male soldier is m1 garand . for female ones is M1 carbine . the reason is simply ammo , spare part , cleaning kits , ammo clip , magazine .american weapon are much more advance than ****ty french , japs thing left over . ammo also much more available