Wood Concrete

Blocks of sawdust with lime and portland cement stop 42 caliber gun but not a 9 mm.

https://youtu.be/SRuJFyoAmKk?si=3mkPUDvJELbsixan

https://m.youtube.com/@WeberMachineWorks

Does the guy make his own brick machine?

Try these in the CEB machine at low compression.