I don’t think of it as a boondoggle. It would have been amazingly cheap to launch solid metal missiles without needing fuel. This would have allowed ships to have more missiles on board.
They just found something better in the form of lasers.
“They just found something better in the form of lasers.”
About the time naval guns became super-sophisticated, autoloading, remote control weapons stations, they were obsoleted by missiles on smaller boats and lasers on large ships. That doesn’t mean such guns will vanish, especially on craft that do not mount sophisticated radars. But they will be more rare.
The point is, some technologies that seemed like a great idea at the time, can become obsolete even before they get fielded. Actually, that’s the ideal time to find out something is obsolete. But the science behind some of these developments may get carried forward in unexpected ways. Microcircuits, heart implants and the internet all had their start on military projects.
The launcher ate its rail electrodes with every shot, requiring a complete rebuild after a dozen shots.
Since they were rail mounted, their locations could be easily pinpointed. The superguns also required vast resources to defend them.
They also found that materials science is not up to keeping the barrels from melting.