From what I`ve read a bullet looses little velocity as rule when it recochets on a shallow angle. The change in the bullets BC from contact damage will cause a lot of variation in how far it will travel.
I tend to go with this explanation if the range is short (200 yards or less). Shallow angle ricochet will loose little velocity but the bullet�s deformation might cause a greater velocity loss.
But for a 1,000 yard ground strike, the bullet will probably be angling down pretty steeply and hit at a high angle. It might just break up pr penetrate into the earth.
