>First of all, the clear blocks being shot are ballistic gel. These dense blocks are tough, elastic, and a common sight in firearms testing because they reliabl

>First of all, the clear blocks being shot are ballistic gel. These dense blocks are tough, elastic, and a common sight in firearms testing because they reliably and consistently measure things like bullet deformation, fragmentation, and impact. To be honest, it's really because ballistic gel reliably and consistently measures things like "the effects of bullet wounds in animal muscle tissue"[0] (i.e. how well bullets kill living things). [0]https://en.wikipedia.org/wiki/Ballistic_gelatin https://en.wikipedia.org/wiki/Ballistic_gelatin