Ok, but Santa Claus is still real right?
The Built a Bunker Backstop article.
From my experience sand in plastic bags that get punctured generally runs out of the holes, after a shooting a ten-shot group on all of the four targets, the next thing you would require in missing illustration No.13 is a shove to put the sand back in the plastic bag after you have patch up the holes.
And the raw edges of the front of the slabs should be covered by a material that doesn’t cause ricochets.
And if you have young children you need to keep them well way from this structure as it has the potential to cause them serious injury if they play on or even in it.
Ok, but Santa Claus is still real right?
Better to admit you walked through the wrong door than spend your life in the wrong room
For a back stop I use breeze blocks as these retain the pellets with no ricochet and not as messy as sand it also not very noisy and will cost the same as a bag of sand
Use Hessian bags for sand & damp them down so the sand clumps.
I’ve got a 12” square box with a 6” square opening at the front. It’s rammed with a load of old wool jumpers, pellet strikes are completely silent.
I've something similar - box is made of 18mm ply, target holder at front is a shop bought thin MDF clipboard that sits in a sawn groove and it's loosely stuffed with old t- shirts, etc...
Silent and catches everything before it even gets to the the wood at the back and goes in the shed when not in use.