"What do James Holmes, Adam Lanza, and Omar Mateen have in common? Besides being the perpetrators of three of the deadliest mass shootings in U.S. history, they all share a preference for the AR-15 assault rifle. The AR-15 assault rifle was used at the Aurora, Colo. shooting, the Newtown, Conn. shooting, and now the mass shooting in Orlando, Fla. that killed 50 and is officially the deadliest such massacre in U.S. history...While Colt alone makes the official AR-15, variants and knock-offs are made by a huge number of gun manufactures, including Bushmaster, Les Baer, Remington, Smith & Wesson (swhc, +0.00%), and Sturm & Ruger (rgr, -2.04%), just to name a few. TacticalRetailer claims that from 2000 to 2015 the AR manufacturing sector expanded from 29 AR makers to about 500, “a stunning 1,700% increase.”"