A friend of mine has a ranch that borders a dry lake bed and we set up our range shooting out at the lake bed. The lake bed is bit more than four miles across and fairly flat. When it fills with water in the rainy season it is no more than four feet deep.
What we have seen from shooting over the lake bed is that ricochets are kind of like skipping stones on a pond. The first "bounce" is pretty long, but it is followed by shorter, faster, bounces. Bear in mind this lake bed is very smooth. It has a fine layer of hardened salts coating it so we don't see odd-angle ricochets.
Shooting things like 30-06 or 8mm Mauser we've seen as many as seven or eight bounces. We've even used binoculars to watch them skitter across the desert.
Rifles like the AK (7.62X39) and .223 don't bounce nearly as far or as many times.
Pistol ammo only gets three to four bounces.
That said, I don't really consider the risk of ricochets to be too severe.
I've been hit by a number of ricochets. Twice they've broken the skin, but they were just a scratch. The one that hurt the most was fired from an 8mm Mauser using armor-piercing ammo. I was curious about its penetration and power and fired at a lava rock at about 100 yards. It came back and hit me in the sternum. It raised a small welt. It did hurt like the dickens and I recall feeling somewhat faint for a moment, but it passed quickly.
At a pistol match last month I got hit with a 9mm ricochet that came from fewer than 25 yards total distance from the muzzle (off of a pepper popper that had been turned sideways by the first shot). It hit my forearm and I got the tiniest little scratch. (Not including it in the ones that made me bleed.)
I live 1.3 miles downrange from a 400-yard rifle range. No one in my neighborhood has ever complained about a bullet issue. A few gripe about the sound of gunfire, but not too many. This is, after all, Arizona.
My sons enjoy our proximity to the range. They can now distinguish a .45 from a 9 or .40 at a distance of 1.3 miles. They sit outside on match night and listen for "daddy's gun." It's the .45 with the boom, but no crack...
I love it because almost every day I am reminded the Second Amendment is alive and well. I know that every time I hear the sound of gunfire to the west...