Hi, I'm a Nam Vet, USCM served RVN 69-70. I've read your post question about the drug use. Well, it wasn't as rampit as you may have heard about. Yes, some men did you drugs but those guys were less than 1 percent of the total troops overall.
I for one did use a drug in Nam only during our stand down, which are free days knowing you were not going out into the field for 2 or 3 days. Most of the drugs I used were Pot or Buffalo sticks also known as Tystick. These were made of Water Buffalo manure and pot not ever good weed at all. The other drugs were Omie bottles these were speed juice, liquid speed.
To be very honest with you in my unit anyone every was high while in the feild we made sure they would be gone once we returned to base. While in the field you held every mans life within your hands and that went for every man in the unit. NO ONE, in the unit would tollerate a guy who was high in the field. I only am speaking for my self and my unit. I do know there were some that did things otherwise but not in my unit.
My standard gear well, I was in the Marine Corps and while on patrols I wore my flak jacket about 30 pounds and ammo another 15 pounds, this was daily action. During an operation you may carry the same or carry more depending on the type of operation it was. If your unit was going out into the field for 2 or 3 weeks its full gear bud max 60 + pounds including 81 and mick mick 60 mortar rounds pluse M60 ammo, extra ammo, flars, grenades tec... get the picture....80 percent of my time was waring my flak jacket with grenades and extra magazines for my M14.