Wouldn’t it depend on what’s IN the shell? Pink mist is probably good enough for Son of Nut.
I have never heard of a mortar round that totally turns all parts of somebody to vapor. They are small arms. There’s just certain limits to them because there’s a size limit to the amount of explosive that can be placed in one. there’s always parts left because the blast of the explosion hurls parts away before they can get vaporized. Grenades don’t turn someone into nothing, essentially this is what a mortar is, a aimed, flying grenade.