[–] i_scream_trucks 0 points 1 point 1 point (+1|-0) ago (edited ago)
im willing to bet it was something that was made up in the field as an ad hoc device by an explosives expert and was never a formal military issued thing in itself. This is vietnam war era and we are well past knowing about agent orange and the kinds of shit that caused, i doubt there would be much 'top secret' stuff from back then left to reveal, and even so, that kind of thing you wouldnt think of really needing a hell of a lot of er... protection to keep it a secret, its just a bang board not some secret squirrel knew kind of radar, or some kind of holographic projector device AKA Quaid in Total Recall, so if it was a legit thing, it would be listed somewhere with some kind of model/serial number, or its just something that was cobbled together in the field as a bright idea borne out of necessity.
wouldnt be a hell of a lot different to throwing a grenade to one side, or over the top of an enemy, not to try and kill them with the grenade, but to make them think the grenade has come from a different direction and get them moving the direction you want them to - or for intimidation, if you ad cut communications lines in you might get, "holy fuck Thahn Nguyen what sized fucking army just took on the units at our flanks? fuck thats a lot of gunfire man..... and i cant get a hold of them over the radio... i think we fucked now, do we get the fuck out because we about to be wiped out by a massive OPFOR or do we hunker down and see just how large it is?"