I use it to 1-shot a phantom's barriers(on gold and platinum) and other bosses in a few shots. And to stun multiple enemies at once while applying ammo powers to set them up for combo explosions. Often times doing all this by bouncing the round off walls and around corners where they can't even hit me back.
So its definitely not worthless its actually one of the best weapons in the game.
You have one or more unread System Notifications. Please read them as soon as possible ^^ http://www.youtube.com/watch?v=ZEf5VFKplzw