Out of the estimated 434 million firearms in civilian possession in the U.S., roughly 20 million of them are AR-15-style rifles, according to the National Shooting Sports Foundation. From the ...

These rifles are widespread. The Washington Post suggested last year, citing survey data, that about 1 in 20 Americans owns one. The AR-15 style also was used by mass shooters in Sandy Hook ...

Here’s What You Need to Remember: Although internally different from a typical AR-15, pistol-caliber AR is essentially identical in operation, with the same loading, manual of arms, and jam ...