I live out in country where it is legal to shoot guns, even though I am at the end of a dead-end road and have my range where I am shooting down in a hollow, I have had too many instances when someone was shooting a long way away through the woods and their bullets came whizzing by me, bullet travel is unpredictable.
I decided to build a bullet trap to be on the safe side. I already had the structure up before I found out that a foot of sand would stop just about any bullet. My trap is a bit of over kill with 3' of sand behind the targets.
According to an online sand volume calculator my trap will hold 1.8 yards of sand or 4800#. My trailer has a 3500# axle so I thought hauling one yard (2400#) at a time would be a good idea. My trailer is 40 years old and has second hand tires, it was a relief when I pulled into the driveway with my sand and trailer intact. Even one yard was heck of a load to haul, I won't try to haul that much again.
I built my trap out of cedar posts and 2X12 repurposed lumber. I soaked the already weathered boards with used motor oil to prevent any future rot.
This is a no shovel sand project; my trailer is parked on a slope and I can rake sand into the bucket easily.
I added a thick horse stall mat to the front of the trap, they are supposed to be self-healing when you put a bullet through them.
I put up some more boards on the front to keep the mat from bulging from the weight of the sand, to reinforce the structure and for target attachment.
I unloaded half the trailer, it started to rain, our first in over a month so I put the project off for a few days. The calculator was right, I can see the load of sand I brought home will only fill the trap about 2/3 of the way.