Because Earth is a rotating sphere, the Coriolis effect deflects the flight of a bullet to the right in the Northern Hemisphere & to the left in the South. The effect is tiny in most practical shootings and only needs to be considered in long-range shootings.
Many soldiers are not trained to account for the Coriolis effect, & flat-Earthers use it to “prove” it does not exist. In reality, most soldiers do not shoot long range. It is unnecessary to consider a few mm of deflection if the target is as large as an enemy soldier.