The lore filtered down from American ground forces in Vietnam—and later from those in Iraq, Afghanistan and other conflicts—was that the M16 and its related M4 platform worked well when they worked, but sometimes failed spectacularly under various combinations of dust, dirt and heat.
Survival in any sense of the word always involves blades, but not, as pop culture would suggest, for fighting off the zombie hordes. The idea that you can survive the apocalypse with a really cool katana is just going to get you killed. We have guns with which to fight, and bringing a sword to a gunfight is well—you know, kinda dumb.
This is the story of a "potato digger," more accurately a Model 1895 Browning belt-fed, air-cooled machine gun. The Model 1895 was designed by the creative genius of John M. Browning, manufactured by Colt and was the first American machine gun ever manufactured.