During my tenure in Germany, the Army had decided that soldiers on guard duty would no longer be issued live rounds. Apparently this decision was based on a large number of suicides which seemed to occur when soldiers were left alone all night pulling a miserable duty shift in a miserable part of the world. However, what this meant for me personally was that every night that I pulled guard duty at Sickles Army Airfield, I was supposed to guard an entire flightline of very expensive Army aircraft with no way to defend either them or myself. (Remember that "Military Intelligence" is an oxymoron.)
Actually, I didn't even have an unloaded M16 as some guards had in other areas of the world; apparently some of the locals had discovered that the guards were carrying unloaded M16s and attempted to steal one by overpowering some poor guy on guard duty. After that incident had occurred, no one carried an M16 on guard duty anymore. This meant that the only two things with me which resembled weapons were a cheap, wooden Billy Club and my three-battery Maglite.
However, that was not the case when the 511th deployed to the border; whenever we were within the 1K zone, we always had our M16s, with three live rounds in one of the guard weapons and a sealed case of rounds hidden in reserve. Depending on the deployment site, the guy on radio watch would have the three live rounds in a magazine of his M16, and the roving perimeter guard would carry an unloaded M16. (Once again, this was to serve the dual purpose of cutting down on suicides and preventing a loaded weapon from being stolen.) The three live rounds were supposed to be enough to fire warning shots if a potentially-threatening situation ever presented itself, and the sealed box of rounds was kept in reserve for the unlikely event that full hostilities erupted.
That being said, in all my time at the border, even though one of the guards had three live rounds in a magazine, there was only one occasion when someone ever felt the need to load them.
During one of our deployments near OP Alpha, SPC Terry was on radio watch and I was the roving guard when a group of three nosy civilians bypassed our "You Will Be Shot" signs and started poking around the perimeter of our site. Everything was surrounded by a triple-ring of concertina wire so they could not get close to any of the equipment, but still - we didn't want anyone nosing around our location.
I think it was SGT Bullard who tried to warn them away in German, but they weren't leaving. After a few, tense minutes of arguing back and forth with the civilians, SPC Terry had had enough and started to walk over to our position. And as he did, he pulled back on the charging handle of his M16, and when he released it we all heard the audibly familiar and oddly reassuring sound of a 5.56 round as it slid into the chamber. There was no mistaking what that sound meant; that M16 was now ready for business - all SPC Terry needed to do was to rotate his M16's safety knob to "Fire" and point the weapon.
And yet these civilians still would not leave, so CW2 Klebo ordered one of us to "Hit one of the civilians hard enough to knock him on his ___." I don't recall if it was SGT Bullard or someone else from our group who complied with the order, but someone other than me used his M16 to execute a textbook "Butt-Stroke to the Chest" maneuver and the guy went flying backwards, after which the injured imbecile unleashed a tirade of German expletives as the three civilians quickly hobbled back to their car and angrily drove away.
To this day, I still think that these clueless civilians had it coming; they had walked past several signs which made it clear that entry into the area was forbidden and the use of deadly force was authorized, plus we had someone who was fluent in German explain several times to them that they needed to leave. Despite all of our efforts, we eventually needed to make our point in a more forceful manner; and if the situation had continued to escalate, it was good to know that someone with live rounds was standing only a few feet away.