abstract:A drum magazine is a type of firearms magazine that is cylindrical in shape, similar to a drum. Instead of rounds being stored flat, as in a more common box magazine, rounds in a drum magazine are stored in a spiral around the center of the magazine, facing the direction of the barrel.
Investigators also found a drummagazine, capable of carrying 100 rounds of ammunition, which was attached to the AR-15 rifle, two law enforcement officials said.