I think anyone who uses the "over the shoulder" right mouse button aim has probably experienced this. You shoot but nothing seems to be coming out of your gun, you look closely and see the bullets are flying way right. You can then press alt to aim down sight and the shots are right on. You can recreate this issue super easily at camp Kodiak on the downslope where the skell credits guy likes to run to. There is a motorbike and boat down there. If you go halfway down the slope on the left side of it you will almost always get this bug.