First of all, correctly it is called the Coreolis Effect. That's 'Effect' and not 'Force'. Secondly, it effects major masses such as high and low pressures systems in the atmosphere and ocean currents. It is why low pressure systems spin clockwise in the Southern Hemisphere and anti-clockwise in the Northern Hemisphere. It does not cause the water in the loo to spin a given way despite common belief.
People speculating that the Coreolis Effect could or would cause a bullet to move differently in north of the Equator than it does south of the Equator that causes me to believe even more that the whole story about .303 bullets 'crossing over' is speculation turned gossip turned 'gospel'.