Overshooting your target may not always be a bad thing. Heavy Back-Roller will make room for your overestimation's . The upgraded tier has double the damage and bigger the blast radius for more effectiveness, giving you more reason to use this weapon if you don't know where to aim.
Back-Groller is quite a paradox. It rolls backwards, but grows. The bigger it is, the more damage it does. Figuratively it moves forward in maturity, but still rolls backwards. So, is it progressive or regressive? You'll figure it out. This tier is a more risky weapon than the previous tier since it can go either better or worse depending on how long it was rolling, it deals 5 damage at its smallest and 48 at its biggest. Use this more wisely than the first and second tier.