Blast Box: You probably want to make one

If you like to check your zero on an AR or AK, zero that hunting rifle, or build and test guns. The Blast box, especially a tire (Video Below) or DWC (Pictured Above) design, is ever lasting. Unlike the wooden ones that fall apart and are prohibitively expensive these days. The tire or DWC is superior in every respect to the lumber.
Any cheap old tires will work. And you can shoot your guns guilt free any day, all day. You don’t need to use old motorcycle tires. A used economy tire costs about $8 if you are short on spare tires. And you will need about 8 of them. Make sure you get the same size. A few pieces of old lumber or timbers work well on both sides of the tires to hold it in place. The setup below is a little complicated… I would just build mine on the ground.
You don’t need to seal up both sides like this video demonstrates. Simply having something there makes your rifle significantly quieter. Your neighbors will thank you. Imagine being the guerrilla unit in the woodline who randomly fires loud bullets to confirm zero. Or, you can make something that completely changes the audible dynamics of the gunshot.
Where my friends live in Maryland it is legal to shoot, but I feel bad for the neighbors some days when  we are firing several hundred rounds of 5.56.

Observe how effective these are. Nearly any design works A LOT better than nothing.