The scourge of armor in Vietnam.
Pretty much took the fun out of riding in M-113 APC....
And the newer models-RPG-28 through 32 series are very nasty. Disposable launcher, much like the old LAW. But some have a new two-stage projectile.
A lot more than armor.
Not so much as the B-40, the Chinese copy of the earlier Soviet RPG-2. They'd cut through the aluminum *armor* of an M113 ACAV or M551 Sheridan light tank and leave them a burned out, melted-down shell. The B-40 was lighter and easier to move long distances than the RPG-7, though a bit iffy about taking out the frontal armor of an M48A3 tank.
Not that the RPG-7 *Knout* wouldn't do the job. But for a tank gunner at night, the backblast of a RPG-7 was an instant call for co-ax machinegun return fire or a *black can* or *green can* canister round. The slightly lesser firing blast from a B-40 could be mistaken for a grenade going off, and at times when LOTS of grenades were going off, that could make things interesting.