Regular troops were not issue live ammunition during exercises and or maneuvers. At the height of war in Vietnam, even troops at the firing range were issued ammo usually one at time. There were very rare instances where a few troops would have 5 to 7 rounds for a walking part of the rifle range. Where the shooter walks and finds and shoot targets over a distance of about 300 yards. But at a stateside fort/base troops would never be issued the amount of ammo seen in the opening scenes of this episode. Even men pulling perimeter guard in stateside location are not carrying loaded weapons. The military maintains close tabs on every round of ammunition.
There has never been and never will be lights in the back of a deuce and half or 5 ton truck.