Why close-in weapon systems need magazine depth

Is Phalanx still an adequate close-in weapon system?

It can handle limited attacks, but its magazine lacks the depth required for sustained defense against a peer threat.

The panel calls the basic Phalanx design outdated and extends the same warning to land-based C-RAM. These systems can work very well when the opponent has only a small stock of incoming weapons. Against a peer threat, however, the defender must survive repeated or simultaneous attacks. Magazine depth becomes as important as tracking and rate of fire because an empty close-in mount no longer protects the ship.