While the U.S. Navy is reportedly struggling to build cannon-sized railguns for its ships, not only has China already put a railgun-armed ship to sea, it is now showing off rifle- and pistol-sized versions being fired at targets.
The weapons were featured in a video on Chinese military news website js7tv.cn last month, and were said to be developed by the Logistical Engineering University of the People’s Liberation Army, considered one of the country’s top military research institutions.
The weapon is known as the Small Synchronous Induction Coilgun, and it was demonstrated in pistol, rifle and robot-mounted variants, bursting balloons and punching holes in wooden and metal targets.
The idea for such weapons is not new, having been around since at least the 1930s. The idea is that by using electromagnetism to accelerate a bullet, you can overcome the limitations of gunpowder-style firearms, which generally top out at muzzle velocities of about 2,000 meters per second. Magnetic propulsion can in theory reach any speed; it is also silent, and with no explosive gases to disperse it can have an extremely high rate of fire. Science fiction fans will have encountered such weapons under names like Gauss Rifles or Mass Drivers, or the shoot-through-solid-walls electromagnetic pulse guns toted by Arnie Schwarzenegger in Eraser.
Arnie packing railgun rifles in the 1996 movie Eraser. The real-life version may be made in China.
Coilguns and railguns achieve the same thing via slightly different mechanisms. A railgun has two parallel conducting rails with a sliding armature between them. The armature is propelled by a high-amplitude current – sometimes more than a million amps. A coilgun is a series of electromagnetic coils laid end to end which attracts the projectile down their centerline.
Coilgun animation
Coilguns are more complex than railguns, which is why the latter have so far been preferred by the U.S. Navy and others. Building a basic, portable coilgun does not require a major research laboratory though; this article from Nuts & Volts magazine from 2008 shows you how to build your own. The makers found that their design could propel an 8-gram .30-cal bullet at a respectable 129 feet/39 meters a second — much less than a firearm but a good proof of principle.
The name of China’s new Small Synchronous Induction Coilgun suggests that it is a relative of the much larger “15-stage Synchronous Induction Coilgun” reported by Chinse researchers in 2012, which fires a 120mm projectile. This used a sequence of fifteen coils that were all energized by the same pulse of electric power, a technique which simplifies the challenge of timing the coils precisely. Chinese researchers have also been working on a four-stage coilgun, and later coilgun work has focused on increasing the efficiency of converting electrical energy to bullet velocity.
The weapons in the new video are more impressive than the Nuts & Volts home build weapon, but on closer inspection appear not that awesome. The balloons are hit at close range; the coilgun pistol seems to go through about four thicknesses of plywood at point blank range, and the rifle about twice that. The thickness of the metal targets is not shown, but they look flimsy. By contrast, a standard 5.56mm rifle bullet will go through more than 25 inches/ 60cm of pinewood board or half an inch/12mm of steel. This suggests that the Coilguns are not ready to displace conventional firearms yet.
The demonstration is still an interesting one, especially the length of time devoted to showing how a toy-tank-sized robot can be remotely controlled to maneuver around and shoot targets. It is not the only tiny robot with a handgun (the Glock-toting Dogo got there first), but it might be a useful urban commando. Inside buildings the short range of the coilgun is not so significant, and the silent firing and deep magazine could make it a dangerous opponent.
The West does not need to be too worried about Chinese coilgun technology on the battlfield just yet. But we should certainly keep an eye on it.
