The U.S. Navy’s Railgun Nightmare Just Keeps Getting Worse

Key Points: The U.S. Navy has, for years, attempted to develop a railgun weapon, spending $500 million on this effort. Sadly, Washington has long abandoned such plans.

However, Japan seems to have made some progress.

The Railgun Challenge

Railguns have long been considered a weapon of science fiction; however, based on recent developments, railguns may one day be employed on active naval vessels.

On April 18, 2025, the Japan Maritime Self-Defense Force (JMSDF) released an image of its state-of-the-art railgun currently undergoing testing aboard the test ship JS Asuka. The implementation of railguns could significantly bolster the offensive and defensive capabilities of Japan’s navy, particularly against the threat of hypersonic missiles from China.

Japan Has Railguns?

The development of Japan’s electromagnetic railgun technology dates back to 2015. The Japanese Acquisition, Technology & Logistics Agency (ATLA) stated that they were working on such technologies under the name “Research on Electromagnetic Acceleration Systems.” In 2016, the Japanese Ministry of Defense revealed an experimental prototype that was able to fire a projectile at approximately 4,470 mph, or 5.8 times the speed of sound. Further demonstrations in 2023 revealed the system conducting its first onboard firing tests.

On April 9, 2025, Self-Defense Fleet Commander Vice Adm. Katsushi Omachi visited the test ship JS Asuka (ASE-6102) to observe the status of the railgun. The Asuka is assigned to Fleet Research and Development Command, which also falls under Self-Defense Fleet Command. Ship spotters took pictures of the Asuka equipped with the experimental railgun while docked at Yokosuka Naval Base on April 9. The ship left the base on April 10 to conduct trials.

Bridging a Critical Defensive Gap

The development of railgun technology has huge implications for the Japanese Navy. The technology would greatly boost the JMSDF’s offensive and defensive capabilities by providing a relatively low-cost alternative to traditional munitions or missiles.

With a speed of Mach 5-6, munitions fired from a railgun rely primarily on their massive kinetic force to deal damage, negating the need for explosive fillings. Railgun ammo also does not rely on explosive propellants, allowing for larger magazine sizes.

Currently, Japan faces a huge threat from Chinese hypersonic missiles. On paper, Japan does not currently possess any air defense system capable of intercepting hypersonics. Japan’s MoD envisions a future in which railguns are used to bolster Japan’s missile defense capabilities. Currently, Japan faces a shortage in interceptor munitions, with a news report stating that Japan only has 60% of the interceptor missile stockpiles necessary for national defense. The railgun offers to bridge the gap in defense capabilities and offer a solution to the hypersonic threat from China.

Railguns Have a Long Way to Go

Despite their advantages, there are still many hurdles to overcome before railguns can be widely integrated. Accuracy is one issue that needs to be addressed. The current munitions used on the railgun are inaccurate, especially when fired in rough sea conditions. Even with hypersonic speeds, the projectile rapidly decelerates due to air resistance, further complicating its flight stability. Japan is currently thoroughly researching methods to ensure consistent flight stability, including GPS guidance systems and various sabot discarding methods.

Fire control systems are also needed on railguns. Such systems are essential to control the launcher, acquire targets based on external sensor data, predict flight paths and impact points, and ensure precise hits on the target. These systems are needed if railguns are to be used as missile defense systems, especially against high-speed targets such as hypersonic missiles. ATLA is reportedly looking into fire control systems specifically tailored for railguns.

Finally, one of the greatest challenges for railguns is finding a reliable power source. Railguns operate using massive electrical currents and magnets to propel their projectiles. This requires massive amounts of electrical power to operate continually. This poses a unique problem for naval vessels, which lack the storage necessary for securing dedicated power generators and storage units. The U.S. Navy sought to combat this problem by installing railguns on vessels with nuclear generators; however, Japan lacks vessels with nuclear power.

Why Doesn’t the United States Have Railguns?

Speaking of the U.S., the Navy was researching and developing railgun technology since 2005. The project was ultimately canceled in 2021 due to “fiscal constraints, combat system integration challenges, and the prospective technology maturation of other weapon concepts.” The project never saw the light of day, likely so that the funds could be used in other, more pressing projects.

Aside from funding, the U.S. also had difficulty perfecting the barrel of the gun. In 2018, then-Chief of Naval Operations Adm. John Richardson told Congress that the weapon had yet to reach its promised range. “That involves a number of technologies,” Richardson said. “The barrel itself is probably the limiting case, the engineering on that, the materials required to sustain that power pulse, and the heat and pressure that’s involved in launching those projectiles.” The barrel and other technological limitations ultimately proved too great for the U.S. to overcome.

Japan still has a way to go before it’s ready to implement railguns on a large scale. However, if the technology is improved and widely integrated, railguns could prove to be invaluable assets against China’s hypersonic missiles. To speed up the development process, Japan has been cooperating with France and Germany’s Research Institute of Saint-Louis to advance railgun technologies, ensuring that the technology will eventually come to Europe as well.

About the Author: Isaac Seitz

Isaac Seitz, a Defense Columnist, graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.