Old is new again with this reliable 1950s-era rifle, refurbished from existing inventories due to a pressing need for a midrange sniper rifle in desert conditions. Pros: Better range and stopping power than the M-16 and M-4 rifles that replaced the â€50s â€relic.â€ Cons: Fires more slowly than the M-16 and M-4, and requires different ammunition. Grade: A
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.