There's an excellent but brief description of both the RPG-7 launcher and the PG-7 shaped charge antitank round for it at the following website. But it should be noted that the PG-7 HEAT warhead is not the only one available for the launchers, or now commonly encountered for the RPG-7 and -14 series weapons.
Still, I somehow doubt that my pointing the article out to them would do them much good....