The M79 grenade launcher, introduced in 1961, could shoot a variety of 40 mm grenades: fragmentation (which exploded into deadly fragments), flechette (cannisters filled with metal darts) buckshot, tear gas, smoke and illumination. The single-shot weapon—carried here in April 1968 by a Marine near Khe Sanh—acquired nicknames such as Thumper, Blooper and Can Cannon. Its simplicity, handy size and weight made it a popular choice when troops needed extra firepower, and it was dubbed the “platoon leader’s artillery.” (AP Photo/Schneider)