I though we might start a new thread to talk about a topic that was brought up in a different thread, which I don't want to totally derail. This post sparked what I think could be a good conversation about gun safety, caliber efficacy, and science in general. The OP asked about 9mm vs 380, which led to someone posting this: As a PSA, please do not try this at home. Hopefully this is obvious to most of us... Hopefully even the OP would agree that attempting this is very dangerous. More than a few people have been killed 'testing' a bulletproof vest. http://wfla.com/2016/09/11/police-testing-bullet-proof-vest-leaves-tampa-man-dead/ http://www.latimes.com/local/lanow/la-me-ln-bulletproof-vest-killing-20150526-story.htmlhttp://talkingpointsmemo.com/livewire/man-charged-murder-bulletproof-vest I don't think kevlar supported by a hard plate would yield the same results as kevlar supported by soft tissue. I know a little about material science and when you change the support conditions, you change the capacity of a product, sometimes wildly. My main question is what was this test supposed to achieve?