But there's no RNG on it i think. If your aim is good and models are clump together (cover), it will hit hard.
This is correct. Of all the RNG in this game, grenades are one of the few tools that do not use RNG at all. All that matters is grenade placement and where your opponet is standing. If clumped in yellow, riperino.
I just wish the shouting cues for grenade warnings were more consistant. Sometimes I hear the grenade que at the beginning of the animation to fire the rifle grenade. Other times the grenade is already mid air.