China has unveiled a hyper-fast machine gun that could revolutionize defense against hypersonic missiles, posing a bold challenge to conventional missile defense systems.
This month, South China Morning Post (SCMP) reported that Chinese scientists are developing a groundbreaking machine gun, dubbed the “Metal Storm,” capable of firing bullets at an unprecedented rate of 450,000 rounds per minute per barrel.
SCMP notes that the weapon, which could become the most powerful machine gun in history, features five or more barrels and is designed to intercept hypersonic missiles traveling at speeds exceeding Mach 7.
According to the report, the project, led by Lu Xutao, an associate professor at the North University of China, employs a novel box-type rotary firing technology with replaceable magazines filled with disposable barrels. This innovation addresses the challenge of refilling ammunition for a weapon that consumes millions of bullets per minute. The electronic trigger system, developed by Lu’s team, uses coils to create a high-energy metal jet that ignites the explosive, achieving a firing time of just 17.5 microseconds.
SCMP mentions that Australian inventor Mike O’Dwyer proposed the Metal Storm concept in the 1990s, but his company declared bankruptcy in 2012. It says that China’s continued investment in this technology aims to surpass the Western prototype by at least ten times in firing rate, making it essential for defending territorial waters and airspace in future conflicts.
Gun-based defenses such as China’s “Metal Storm” have a key advantage over missile defense systems in the sense that they have faster reaction times – they can begin firing almost instantaneously at an incoming threat’s general direction, in contrast to missile-based defenses that take time to detect, identify, track, and engage targets.
However, unlike missile defense systems, gun-based defenses have a very short range – just 5 to 9 kilometers in the case of the US Navy’s Phalanx close-in weapons system (CIWS), limiting their use to point defense scenarios.
Gun-based defenses may also perform poorly when the instantaneous destruction of the target is required. Unlike an interceptor hit that can completely obliterate an incoming missile using hit-to-kill methods, there is a chance that a hypersonic missile still hits its target despite sustaining multiple bullet hits, with its high velocity ensuring heavy damage just by sheer kinetic energy.
Defending against hypersonic missiles presents significant technical and structural hurdles for existing and futuristic defense solutions that face cost, technical, and operational challenges.
Hypersonic weapons, which travel at speeds exceeding Mach 5, exhibit exceptional maneuverability and low-altitude flight, making them elusive for traditional radar and missile defense systems. These flight characteristics allow hypersonic missiles to exploit gaps between air and ballistic missile defenses.
Traditional missile defense strategies and technologies target ballistic missiles at different stages of their flight. When a ballistic missile’s rocket motors are burning to push it into a high altitude, a boost phase intercept may provide the highest probability of interception. This approach requires positioning interceptor missiles close to the target. Ballistic missiles also have short boost phases, lasting only 3-5 minutes, providing a tiny time window for interception.
When a ballistic missile reaches its midcourse phase, it travels through space in a ballistic arc. This long phase gives more time for interception. However, within this time frame, it can deploy countermeasures, decoys, and penetration aids to defeat incoming interceptors.
Intercepting a ballistic missile during its terminal phase requires defending specific targets such as cities or military facilities when it re-enters the atmosphere and closes in. However, this phase has a very short time window for the interception, and the re-entering missile travels at hypersonic speed, making interception very challenging. Hitting a maneuvering target like a hypersonic missile would add even more difficulty to an already daunting task.
In February 2022, Asia Times noted that the SM-6 Dual is the only US interceptor missile with some degree of effectiveness against hypersonic threats, and even then, its capability may only be marginal.
Cognizant of the SM-6 Dual’s shortcomings, a June 2024 US Congressional Research Service (CRS) report mentions that the US is developing interceptors such as the Glide Phase Interceptor (GPI) and Glide Breaker projects to defeat hypersonic threats.
However, these interceptors’ high costs and long production times may make them unfeasible against a saturation hypersonic missile attack. Also, the limited magazine depth of US warships caps the number of interceptors they can carry.
While directed energy weapons such as lasers and microwave weapons have been touted as the future of missile defense, promising instantaneous hits with a practically unlimited ammunition supply at negligible cost, the technology has yet to deliver on its promise.
In January 2024, Asia Times noted that key limitations in the US laser weapons program include the need for substantial physical, weight, power, and cooling space, which current US surface combatants lack.
While US projects such as the HELIOS laser and the Optical Dazzling Interdictor Navy (ODIN) systems exemplify ongoing efforts, technological maturity issues persist, such as improving beam quality and control. Further, the US Navy’s Arleigh Burke-class destroyers, already maxed out on upgrade potential, face internal space constraints, limiting the installation of new power generation systems necessary for laser weapons.
Railguns, which use electromagnetic energy to propel a projectile instead of explosive propellants like traditional guns, have been explored as a possible defense against hypersonic weapons, akin to shooting down a bullet with a bullet.
However, as with laser weapons, railguns have substantial physical, weight, power, and cooling space requirements. Further, current railgun technology only allows for a few shots per barrel, as the intense heat from firing warps the rails that conduct electromagnetic energy to propel the projectile.
Given these constraints in existing and future counter-hypersonic defense systems, one feasible option would be to go against their kill chains spanning multiple domains – the people, processes, and assets necessary for a successful hypersonic missile attack.
However, Asia Times pointed out in December 2024 that multi-domain operations (MDO) may be the latest military conceptual boondoggle. Most concepts lack a clear theory of victory, frame adversaries in general terms, have overly optimistic assumptions about technological capabilities and possibly downplay the challenges posed by inter-service rivalry and whole-of-government approaches.
