I shoot everything from .22 to .50 BMG on my property.
When I was building the range, I was wondering what to use for a backstop. I thought about hauling dirt in, but I figured that it wouldn't be a very good solution. Why? Well, you need quite a bit of dirt to get a height of even 4 or 5 feet. Secondly, the face of the mound is at an angle, which increases the chance of ricochet. Third, dirt freezes in the winter, which increases the chance of ricochet even more.
If it's not already obvious, the design of your backstop should minimize the chance of ricochets.
So here's what I did: I had a bunch of railroad ties delivered, and I stacked them up about 4 feet high and three ties deep. This setup has the following advantages:
- Simple... just stack ties using tongs.
- When ties get shot up, simply order new ones and/or make rearrangements to the existing ties using tongs.
- The ties form a wall that is approx. orthogonal to the direction of the bullet. This minimizes ricochets.
- Unlike tires, railroad ties are not an eyesore. And they don't hold water. (Tires hold water and become mosquito breeding grounds.)
- If you ever move, the railroad ties probably won't be a problem. But if your backstop is made of tires, you will probably have to dispose of them.
- When the railroad ties get shot up, they simply degrade.
- A wall that is three ties deep will stop a .50 BMG round.