For what it's worth, in New York City, if you wish to open a commercial range, the plate steel must be angled at exactly 45 degrees. Miss that angle by one degree and your range did not get approved. Once the bullet is directed toward a sand trap after hitting a sloped steel sheet set at 45 degrees, the chance of ricochet is nill but of concern is bullet splatter. Bullet fragments are dangerous to the eyes (always wear eye protection while shooting) but do not cause serious wounds. I should know, I've been hit by many as a police firearms instructor.
For an intact bullet to be re-directed toward the shooting line, something down range was not installed properly.
