A motorized magazine loader for loading cartridges into a magazine includes a powered sorting and lifting wheel rotatable about a horizontal axis of rotation, a vertical gravity fed cartridge chute positioned laterally next to the sorting and lifting wheel, an accumulator portion at a lower end of the chute, and a loading portion comprising a receiver for magazines to be loaded and a pusher mechanism for inserting cartridges into the magazines, all supported and substantially contained by a housing. Control circuitry includes jam mediation system.