In one of our conversations about known but insignificant ballistics phenomena, ballistician Homer Powley put the matter in perfect perspective --

"The moon affects the trajectory but not enough to worry about."

(because the bullet is an infinitely tinier mass than the coastal waters of an ocean)

Photos by the old Winchester lab show that as far as the ultra-high-speed camera can show, the bullet is on its way -- inches beyond the muzzle -- before the rifle starts to move backward discernibly.