I was infantry when infantry walked (2/502 Inf 101 Abn Div, RVN 67-68)
We went to the field for 30-60 days, sometimes more.
To give you an idea, the average infantryman in the South Pacific during WWII spend 100 days in combat in 4 years, the average infantryman in Vietnam spent 270 days in combat in 1 year.
We carried everything in our ruck, you never got away from your ruck, NEVER.
It was your lifeline. Even during short night ambushes, you took your ruck.
This habit stuck with my in my Alaska National Guard days where I'd get caught out during the winter. The Ruck is your lifeline.
I still do it. I carry my ruck in my truck now, but I still have it on any road trips I may take. In addition to hunting and fishing.
In Vietnam we got resupplied every 5-7 days, IF THE CONDITIONS PERMITTED. You had to be prepared for extended periods where you couldn't get resupplied.
You quickly learned what you could do with or without. Weight was critical.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071