This rocket has fairly average statistics for an explosive – the direct impact of the rocket is of course an instant kill due to its weight and the ensuing explosion deals significant damage to any lightly armored targets. Although, heavily armored stalkers, notably those in Exoskeleton armor, may surprisingly survive the blast.
OG-7V warhead can't be bought from any of traders (excluding RPG from Hermit for 49999 RU) and none of NPCs uses RPG through whole game (excluding one Clear Sky member at the end of hospital in Limansk who's not accessible to player), so ammunition is almost impossible to find. Nimble will sell you info about stash in Great Swamps with one rocket for 2000 rubles, Hermit in stalker's base in Agroprom also has information about one warhead in Agroprom Underground (not accessible after flooding it). Raven can sell you info about another rocket in military base (albeit he disappears after talking to him when getting second time to Army Warehouses). After talking to Hog about getting to the radio transmitter in Army Warehouses player will automatically get information about stash with RPG near destroyed tank in middle of base. Finally, two more stashes contain one rocket each (one in safe in swamp near chemical anomalies in Garbage and one in Zaporozhec standing near Forester's outpost).
Fragmentation warhead for anti-personnel warfare used with the RPG-7u grenade launcher. The main purpose of the warhead is to kill enemies in cover outside the range of hand grenades using the RPG-7u launcher. - Ingame OG-7V warhead description
In Pripyat, in the underground tunnels below the Grocery Store, to the left from the ladder there is a RPG-7u and one warhead hidden behind a steel framework. It is very hard get the warhead, grenades might be needed to move it in order to pick it up. It is visible from the metal grid which is partially transparent.
It should be noted that the rocket for the RPG-7u in the game has mistakenly picked the wrong image. In fact the real life counterpart for the warhead depicted in game is the 93mm PG-7VL HEAT. The 40mm OG-7V HE-Frag is an anti-personnel rocket but it's "pencil"-shaped. Here is the comparison using real pictures:
In a popular Discovery channel's show, MythBustersSeason 09 Episode 13 - Bikes and Bazookas, they were testing the 70mm PG-7VM warhead. The content of this episode might help to understand why such a "cone shaped" warhead is anti-armour rather than anti-personnel.