The weapon with the bump stock also has a Surefire 100rd magazine in it

EXCLUSIVE: 2 of the 23 guns found in #LasVegas suspect’s Mandalay Bay hotel room. Photos obtained by @JacquiHeinrich https://t.co/PX0w8X167U pic.twitter.com/wwnc8MWdPO

— Boston 25 News (@boston25) October 3, 2017

The one on the left has a bump fire stock on it. It’s a device that accelerates semi-automatic firing. https://t.co/8qmjMPEnl8

— Stephen Gutowski (@StephenGutowski) October 3, 2017