AR-15 is a “genericized trademark” describing rifles that are based on a design developed by Armalite and later sold to Colt. The AR-15 was originally built as a smaller, lighter version of Armalite’s AR-10, chambered in 5.56 NATO round. The AR-10 is chambered in the larger 7.62 NATO. Armalite later sold the rights to the AR-15 design to Colt.
While there are some companies that claim to make an AR-15 style shotgun or AR-15 upper receivers chambered for a .410 shotgun shell, not only have I never actually seen one, but there has been no information to indicate the shooter had such an uncommon firearm.
Twitter was quick to ask CNN where one of these “AR-15 shotguns” could be found:
Where does one procure an AR-15 shotgun, @CNN? Asking for a friend.
— Kemberlee Kaye (@red_red_head) September 17, 2013
— Sharky Sharkerson (@gwshark11) September 17, 2013
— ZomBeasley (@MikeBeas) September 17, 2013
— Jacqueline H. (@liberty_penguin) September 17, 2013
— Ryan Daugherty (@Ryster99) September 17, 2013
Others wondered if CNN was pivoting into the comedy market:
— Rob Tam (@robtr2) September 17, 2013
CNN says the shooter had an AR-15 shotgun? Probably uses a flintlock mechanism and is colloquially known as a blunderbuss.
— Nathan Wurtzel (@NathanWurtzel) September 17, 2013
AR-15 Shotgun. CNN seems to be in competition with THE ONION: http://t.co/rkrpalltEc
— Jai (@JaiSimon) September 17, 2013
On a parting note, Dana Loesch points out that an “AR-15 style shotgun” still isn’t an “AR-15 shotgun.”
And an MKA 1919 still isn't an "AR 15 shotgun." Just like my kid's AR-15-looking BB gun isn't an "AR-15 BB gun."
— Dana Loesch (@DLoesch) September 17, 2013