>Unlike military counterparts like automatic M-16’s, rifles like those from Bushmaster don’t spray bullets with one trigger pull. But, with gas-powered mechanisms, semiautomatics can fire rapid follow-up shots as fast as the trigger can be squeezed. They are often called “black guns” because of their color. The police tied a Bushmaster XM15 rifle to shootings in the Washington sniper case in 2002.

Has nothing to do with the article, but they just can't resist.