At 500 yards, the trajectory of a 308 Winchester 175 gr. Sierra boat-tail bullet is about 161 inches (that's 13 feet) for a 1000 yard target. See: http://images.google.com/imgres?imgurl=http://home.comcast.net/~jesse99/competitiontablemoa1000yards.JPG&imgrefurl=http://home.comcast.net/~jesse99/longrange.html&usg=__nTuebYI-IyToZr80ygnOaP8INGs=&h=710&w=646&sz=158&hl=en&start=1&um=1&tbnid=ZPojfUEYAcMGXM:&tbnh=140&tbnw=127&prev=/images%3Fq%3Dbullet%2Btrajectory%2Bfor%2B1000%2Byards%26hl%3Den%26um%3D1
At impact, the bullet (I believe) would probably not ricochet, but plow into the ground, deform and not ricochet.
