I found your problem. Your animation frames all had Colission Enabled and Bounce off Surfaces. In addition the ground below them was Solid.
That means that every animation frame, being 5 times bigger than the original Bomb, bounced off of the Solid ground.
Because the frames are so big they also suddenly overlap the whole bounce-off point and that messes up the math/reactions.
The whole calculation basically messed up everything. Remove Colissions or Bounce off and you'll see it works fine : )