Andrew Jackson York has no idea what rifle his father used.

[Scarface]

Let me add this: in Viet Nam you could carry a Thompson SMG, a Grease Gun SMG, AK-47, SKS, Garand, US Carbine, or heaven forbid, an M16. I suspect WWI was very similar to RVN.

What? A Marine serving as a grunt in Vietnam carried, as his primary weapon, what he was told to carry be it an M-14, M-16, M-60 or M-79. True, there was some 'freelancing' with shotguns, captured enemy weapons, M-1 carbines but they were in addition to, not instead of. Vietnam was not a free-for-all.