Odd thing....I was posted from a Unit up north where we were fighting Main Force NVA Divisions.....to down near Saigon where most of the contacts were with VC units....and upon arrival I had an M-16 and a 12 gauge Pump Shotgun.....with a fair bit of ammo for each....and the question asked was....."what are doing with those?".
The natural response was "shoot at folks sometimes.....what else would I do with them?".
Things were a bit more relaxed up north it would seem but then it was far more a real live shooting war up there.
Things changed later on when the Main Force NVA Units began to show up in the Cambodia Border areas.
Seems a lot of agro over a single Round of Ammo during your time.
But then when you are shooting up Thousands of Rounds in a day.....and hitting the FARP Ammo Resupply Point and helping yourself to what you needed....a single Round became quite insignificant.
I preferred calling in 105/155/ and 8 inch Artillery fire missions instead of just pattering back with some 7.62 MG Rounds......as the HE Rounds had more effective than did the Military Ball MG Ammo did.