A device called an “auto sear” can transform a semi automatic gun into a weapon capable of emptying an entire magazine with a single pull of the trigger. Also known as switches or chips, auto sears have been around since the ‘70s but are exceedingly tough to acquire legally in the United States, where machine guns cannot legally be owned without a special license. In recent years, an investigation by VICE News and The Trace has found, these small metal or plastic devices have exploded in popularity on the black market and gained a particular cachet among criminals and anti-government extremists. Help keep VICE News’ fearless reporting free for millions by making a one time or ongoing contribution here. - https://vice.com/contribute Subscribe to VICE News here: http://bit.ly/Subscribe-to-VICE-News Check out VICE News for more: http://vicenews.com Follow VICE News here: Facebook: https://www.facebook.com/vicenews Twitter: https://twitter.com/vicenews Tumblr: http://vicenews.tumblr.com/ Instagram: http://instagram.com/vicenews More videos from the VICE network: https://www.fb.com/vicevideo #VICENews #News