A little known fact regarding the M202A1 FLASH multi-shot launcher, featured in the movie, was actually a "modern" ( early 60's technology ) replacement for the M9A1 fuel-tank type of flame thrower. These, for obvious reasons, were considered far too impractical and dangerous to the troops using it in the field. The M202A1 was loaded with up to four M74 66mm incendiary rockets, each filled with napalm-like fuel slurry compound. It could aternatively be loaded with M96 CS gas rockets for clearing enemy troops from tunnels and bunkers. It never had an anti-armour capability, as the standard disposable anti-tank weapon of choice was the M-72 LAW, already in the inventory.
I've often wondered why this weapon system wasn't retained and updated by the DOD. It could have replaced several weapon systems ( including recoiless rifles ) currently in the inventory at the time, in a mobile, lightweight package. I suppose it could be argued that the LAW allowed more troops to carry an anti-armour weapon in the field, instead of only one or two men in a support squad being armed with the only anti-tank capability.