Backstop construction

Since I've finally got a little bit of land to play around on, i decided it was time to put together a solid, safe backstop so that I can shoot/sight in on my own property instead of bothering my boss and using his.
Just wondering what people on the forum use to stop bullets.
When I'm done ill have about 5 feet of sand piled 6 feet high, backed by about 3 feet of clay and topsoil also about 6 feet high. The width will be between 6 and 7 feet.

Back in Michigan i used a small pile of wood in front of a small hill, and it worked just fine. Most bullets stopped in the wood and never made it to the dirt.

Cross ties....(”retired” wooden railroad rail supports)
They’re usually made of oak or some similar hardwood, treated with some unusually nasty stuff that definitely isn’t allowed today so they’ll last forever.

Stack em up, spike em together, and put a few in as tiebacks into the dirt wall and you’ll have a good backstop. And,...if you’re someone who shoots thousands of high powered rounds (I’m not, can’t afford it, haha) and you chew them up,...you can just stack another wall of them in front of the spent ones and have at it again.

Im guessing they're treated with creosote. I don't shoot that often, and usually not with what i consider a high powered round (others might have different opinions). I'd like to get back to my former level of skill, but its not really neccessary for the kind of hunting i do in the areas that i usually hunt. No need for hairsplitting accuracy when all of your shots are within 150 yards. Inside a few inches at 100 is fine.

Got a hillside I use as a backstop.... cut out whilel putting in the atv path by the log splitter before heading up the hill..... was going to build a rack to hold oak plank cut offs( 4in thick ) from work doubled ,rebar frame , something I could replace the plank when needed.... dont shoot that much , more to check and sightin before the hunting season starts

just through the trailer.... the for sale relator sign

https://i.postimg.cc/RV9ZS04F/copy-I...644-795-71.jpgexxon gas near me now

https://i.postimg.cc/J7SdZyGr/copy-I...29-408-296.jpg

https://i.postimg.cc/BZFCWmn3/copy-I...73-586-382.jpg

50 yrd off the corner of the cabin porch


https://i.postimg.cc/02Q2MBKR/copy-I...612-702-21.jpg

At the gun range I'm a member of, the pistol range has crossties stacked 8' or so high on the side for the 40 yard length to seclude it from the rifle range. IIRC, the backstop has crossties stacked 8' or so high, sandwiched between 2 piles of dirts on the front and backsides.