This is going to be strange.

I'm looking for a 1 shot manga i think about a world where when you shoot your gun the bullet just drop to the ground so in one scene someone shoot his rifle in war and the pullet drops to the ground so some third party halts the battle and calculate the path of this bullet to find that it will hit this guy so the one who was supposed to get shot starts to drill himself.

And when a tank fire the shell they calculate the trajectory to find that it is in the middle of some soldiers so they pile up explosive and blow the soldiers who are just wait to be blown up.

I can't remember the name nor the art style as i did read it very long time ago.