You can go to pretty much any steel supplier and ask for a piece of 1/2" ar400 and that will stop everything in your arsenal and never wear out. I have a piece of 7/8" ar400 and it stops hi-powered rounds like they were spit balls. It turn ss109 steel core ammo to dust while barely scratching the plate. This plate is also more vocal than regular steel since it is so much more dense. it also tends not to rust for the same reason. I am currently considering building these for selling if anyone is interested.