@meso That’s the mesothelioma designator, for guns that used dangerous asbestos-based parts that the government now considers unsafe. That’s actually where the AR designation comes from (the above meme about states is a joke), it stands for Asbestos Reduced, and it indicates that the weapon complies with asbestos safety regulations. When you hear people say that the M-16 and M-4 are deadlier than the AR-15, that’s because of all the unsafe asbestos parts.