The gun was saposidly nearly as powerful as the Yamato/Argo’s main gun. In the first series the Yamato/Argo took a shot from the main gun on Deslok’s ship, which bounced back after hitting a new armor deployed by Sandor, destroying the ship (though Deslok somehow survived). And with it’s hull being composed of material normally found in neutron stars, it would be difficult to destroy. An antiproton beam of that magnitude would be difficult to withstand.
