This afternoon, I launched a 0.12g airsoft round at a Canadian dime (92% steel, 5.5% copper, 2.5% nickel, 1.22mm thick). Predictably, it didn't go through. It did, however, leave an impressive dent (considering the projectile).
So, here's the challenge: shoot your own airsoft gun, be it commercial or homemade, at a Canadian dime, or some roughly equivalent coin. No restriction on the mass of the round you use, so long as it's plastic, 6mm, and spherical. It would be interesting to see at what speed the coin starts bending.
Also, I personally guarantee a donation of $50 to anyone who actually manages to launch an airsoft round through a dime
