DIY Bullet Trap
Built this on a whim using deck boards that were too warped for using on the deck:
Used rubber floor matting from Home Depot. So far it has 21 rounds of .40 cal and none went all the way through.
Mine is one step simpler. I just put a flap of inner tube on one side inside a 5 gallon bucket, then fill it with sand. Tape a target to the same side as the inner tube and fire away. The inner tube "heals" and keeps the sand in as the sand traps the bullets. I fired 30-06 ball into it at 25 yards and it failed to penetrate the bucket. Must be some reason those wise old soldiers love sandbags so much! Of course, about half the sand rained up out of the top with that 06 round.
I use mine for recapturing lead from muzzleloaders, hanguns and rifles so I can recast it. Never have sprayed enough sand to have to refill during a shooting session. When through, I screen the sand and recover the lead.
Of course, there's sand coming out our ears over here. A bud of mine went one step better. Bought a bag of "mulch" made from chopped tires at the garden supply. Works as well as sand and lots lighter. And he doesn't have sand readily at hand.
Not a critique of yours, because I really like that, too. As shooting locations get harder to find, it's more and more on a guy's back to find safe bullet stops.