Have a friend who's son is on a rifle team and needed a place to shoot. They live in a subdivision in the city. He owns a large lot so what he did was set up a steel connex container in the back yard, and covered it with dirt. Cut a hole in the end and installed a 24" culvert, 100 yards long. He used a lazer level, and a lot of hand work, to assure it was level. Then he built a small shed onto the end of the culvert, then buried it. He also installed a pulley system to send his targets down range. At 25 and 50 yards he placed a box with lighting inside. When you are cranking a target down range and it comes into light you know it is 25, 50, or 100 yards away. The entire unit is covered with dirt, and all sound as well as any stray bullets are contained.
Grant built this for his son that shoots .22RF. But on cold days when we got nothing better to do we go out and shoot a few with our 30-06s or .338 Win Mags. Sure beats shooting outside when it's 30 below. Just make sure you got good, I mean good hearing protection. I wear ear plugs, with good ear muff type protection. Noise levels inside that steel box is massive. Someday we got to put in some sound absorbing material. But the neighbors never know we are shooting there, no sound gets out. I have looked at doing the same thing out where I live. But 500 yards of six foot culvert is more than I can afford.