Caldwell's AR-15 Mag Charger is designed to accept loaded rounds directly from any common 50-round ammo manufacturer box or from aftermarket 50-round plastic storage boxes. Align the bullet tips and dump into the Mag Charger. Once filled, insert any AR magazine into the Mag Charger just as you would into a rifle. Each stroke loads 5 rounds as the spring-loaded ammo carrier automatically advances aligning the next five rounds until magazine is fully loaded. The entire process of filling the Mag Charger and loading all 50 rounds into two magazines takes less than 15 seconds. The AR-15 Mag Charger includes an Ammo Transfer Tray to invert ammo positioned in boxes with the bullet tips down or to stage bulk ammo. Highly durable polycarbonate construction, the Mag Charger is compatible with .223, 5.56 and .204 ammo.