In a thread on another gun forum, a user showed us that floor tiles could be used to stop rifle rounds. I decided to test whether it was possible to make homemade "body armor" that would actually work. I'm pleasantly surprised by the results.
I used three PEI grade V porcelain floor tiles with a coat of Herculiner on the front and between tiles and a thick coat (about a quarter inch) on the back to capture fragments. I placed a paper grocery bag behind (to see if anything came through) and shot it at about twenty feet with .223, 7.62x39mm, and .40 S&W. Unfortunately, I didn't know the close range POI on my AK as well as on my AR so I had to shoot it three times with the AK to get a hit where I wanted. The reason is that the first shot was too close to both edges and caused the whole corner to bend back into the paper. I don't *think* the bullet made it through but I couldn't be sure until the third shot.
Afterward, I shot it with an additional ten rounds of .40 and not a single round made it through.
This stuff did quite a bit better than I expected.
Video of test