Howdy!
We purchased some land "out in the country" and have started construction on a pistol to 50' range. Want a safe place for my kids (7 and 9) to shoot.
Wanted to build something that would have less maintenance, be cost effective and measured 10' high X 4' top thickness X 25' wide, with wings for ricochets.
My first inclination was to make a big box out of rail road ties and fill that with dirt. The railroad ties would be there to keep the dirt in place.
Then I realized a few things...
#1 - it was going to take a lot of railroad ties (over 200)
#2 - railroad ties are $26 each (over $5000)
#3 - most of the available ties are in pitiful shape
#4 - I would need something to lift them in place because they are a bit heavy (I'm working alone mostly)
Railroad ties ended up being cost prohibitive.
Found pictures online of retaining walls made from dirt filled used tires. Got to thinking that used tires are used in shoot houses! (more on that later*) Called around to several larger tire shops and found one that would give me tires for free! Problem solved!
Started with used tires and sandy loam to fill them.
Took a week of vacation, 120 yards of sandy loam delivered, and rented a Kubota backhoe. The plan was to build a 10' tall berm with tires on the outside to keep all of the dirt in. Started Saturday and worked 9 long days. With help from the wife and kids on the weekends. Made it to tire row 6, a little over 5' tall, by the end of day 9. Used 120 yards of sandy loam and ~600 tires. At this point the backhoe couldn't put dirt on top anymore. And I was spent.
By the way, it takes a lot of dirt (and time) to pack a tire full of dirt.
At a little over 5' high there was not going to be an easy way to get dirt up there without renting a big excavator, at least with how I had laid out the tires. If I had been smart, I would have made a ramp at each end and used a skidsteer to bring dirt to the top. But I was stuck with what I had started.
*About this time I found out that shoot houses use non-radial tires because radial tires can cause ricochets. Well heck, that's not safe. Now I'll need dirt in front of the tires to mitigate ricochets. Settled on 3-4' of sandy loam in front of the tires.
For the next two weeks tried to figure out what to use to put 5 more feet of dirt on the backstop without spending a few thousand on a big excavator and another week of vacation... Came up with a back retaining wall using 4x4 posts and 2x10s (all direct ground contact #1 lumber). Had to sell a kidney or two to afford the lumber.
Rented a skidsteer and built a dirt ramp to get to the top. Had another 120 yards of sandy loam brought in. Got another 60 used tires to fill out the wings.
Backstop height is a little over 10' with 10' thick sandy loam at the top. Don't have a good way to measure the bottom. The tires were 12' apart on the bottom row. Including the railroad ties, the bottom is around 16' thick. Inside width is 28', the inside edge of the wings are a bit wider.
Starting the 4th row of tires on the main section:
Row 5 complete:
Pic from the back:
Start of row 6:
continued...