There were high hopes for the weapon that the US Navy spent $500 million on. However, this weapon, the electromagnetic railgun, which was supposed to fire projectiles at hypersonic speed, has proven to be unviable. Even after all the investment poured into it, the USN still has not armed any ship with it.
Shifting kinetic weapon tech to other systems
This weapon is being phased out as the Navy switches its emphasis to faster, longer-range weaponry capable of destroying both ships and land targets in a military crisis. Examples of these are hypersonic weapons that can fly at more than supersonic speed, something that Russia and China already have. The 2022 budget asked for by the Navy does not include money for the railgun, reported Yahoo Finance.
Some weapons are not like conventional guns, cannons, and howitzers, as mentioned by Popular Mechanics. Conventional guns shoot a projectile out of the barrel with the pressure of an exploded gunpowder charge, propelling it on a ballistic trajectory. Railguns will speed up a shot down a pair of tracks with electricity and magnetism instead of gunpowder and chemical energy.
Railguns are better than conventional guns since they lessen the amount of volatile powder a ship carries in its ammunition magazine. The projectiles are also faster.
Even with the advantages of the weapon, canceling the Navy railgun project has some good reasoning behind it. It has been going on since 2005 but only three ships, the Zumwalt class destroyers, can use this high-tech weapon. Hence, the Navy is shelving it in the meantime.
Only with the commissioning of the next generation DDG(X) destroyers will the powderless cannon be ready for use, and that won't happen until the late 2020s. So far, no definite plans for the future destroyer have been established yet.
Pursuing the railgun is also not in sync with the current direction of the US in relation to dealing with Russia and China. One of the problems of the powderless weapon is that it lacks the missile range compared to the Chinese DF-21D anti-ship ballistic missile, touted as a ship killer. These metal hurling guns are good as defensive weapons that can track aircraft, missiles, and drones to shoot them down. But other conventional weapons are used to do the same thing but at a lesser cost.
Hypersonic weapons are getting more important
One type of weaponry that is gaining traction is the use of hypersonic weapons, like the Navy's new Common Hypersonic Glide Body (C-HGB). It is being developed with the US Army and can reach Mach 17, with a range of 1,700 miles. The speed it travels and its maximum range make it a weapon of choice for long-distance assaults, cited by Flipboard.
Instead of railguns, the Navy has decided to arm its Zumwalts with C-HGB because it would be more affordable. Armed with hypersonic weapons the destroyer is going to be more lethal.
After shutting down the Navy Railgun project, China seems to be working on its own version.