4 inches of bullet drop at four hundred yards with a 270? And shooting quarters at a hundred is sufficient practice for a 400 yard shot? If you shot steep down hill and only had to hold 4 inches high im gonna say you only shot 250 yards out at most. Too much just dont add up for it to be anything other than luck. Kentucky windage and elevation is rarley anything but luck. Lucky is all it was - lucky you didnt wound that cow.