More at the link.The weapon was new, made of cutting-edge materials. It had demonstrated its capability in the lab and on the range, and the men had such confidence in it, that when a Laotian unit, driven out of Laos by NVA forces with tanks, begged the SF camp commander for anti-tank weapons, team sergeant Bill “Pappy” Craig (who was acting as his own weapons man, having been sent a flaky kid as a replacement who more or less defected to the NVA) gave the Laotians his two old, if proven 3.5″ rocket launchers, aka Super Bazookas. He kept the new Light Antitank Weapons for his own team.
He would live to regret that decision.
In the months and the years that followed the hilltop fight, the Army made many half-hearted attempts to understand why and how the LAWs had failed. The testimony that they did fail is clear: they failed to fire, squibbed, hit the PT-76s and bounced off, hit and didn’t penetrate. And the weakest tank in the enemy inventory, a tank with a bare 15mm or so of armor, rolled over the defenses with near impunity. But most of the investigations were aimed at proving “that couldn’t have happened,” and shoring up the reputation of the M72 which had performed well in tests and poorly in combat.
The most plausible explanation is that long-term storage, careless handling while in storage (in the Army, the hard left of the bell curve goes into ammo handling), environmental problems, or the shock of parachute delivery had somehow affected the functioning of the rockets. The Lang Vei survivors reported so many diverse problems with the weapons that engineers were at a loss to duplicate the failures or even come up with an Ishikawa diagram or failure tree that plausibly explained them.
https://www.youtube.com/watch?v=vV84O7hXR-w