LAW's are inefficient and too heavy. A multishot grenade launcher such as the MM-1 or MGL though....ooooooo, baby!
Had an f2f game a month or two back where one character behind a German H&K Grenade Machine Gun took out about 40 Russian infantry single-handedly in just a few seconds, then turned the weapon on two BTR-80's. The carnage was scary.
And they were just the PC's doctor....