It comes with a 30 round magazine. If you want more or less capacity there are plenty of aftermarket magazines that will fit.

Josh - The capacity of the magazine that comes with this is 30 rounds. Magazines of various capacities are available, ranging from 5 rounds up to 100 round drums. This rifle utilizes a standard AR-15 .223./5.56 magazine.

Joshua, this rifle comes with a 30rd Magazine but will accept any standard AR Magazine or Drum regardless the capacity.