The US military is testing bullets that can be fired underwater, potentially enabling Navy SEALs to engage in submarine combat and sink enemy boats from below.
Water is 800 times denser than air at sea level, meaning normal bullets slow down underwater to the point that they’re rendered ineffective.
The bullets manufactured by DSG Technologies are made from tungsten – a metal with a high resistance to corrosion – and have a small hole in the tip.
This allows a bubble to form around the bullet as it travels through the water – a process called supercavitation.
The bubble reduces the drag of the bullet, allowing it to move more rapidly through water.
Norway-based DGS claims its ammo can travel 200 feet underwater and pierce through two centimetres of steel, fired from 55 feet away through water.
WHAT IS SUPERCAVITATION?
Supercavitation is an extreme form of cavitation – a physical phenomenon in which rapid changes of pressure in a liquid lead to the formation of vapour bubbles.
It can happen when water is accelerated to high speeds, like when turning a sharp corner around a moving piece of metal such as a ship’s propeller.
The bubbles can be large enough to encompass an object travelling through the liquid, greatly reducing drag on the object. This enables it to achieve very high speeds as it travels.
This shape is also effective against targets with fibre structure or mud – even when covered by sand.
DGS says its ammunition doesn’t require the use of any special weapons, claiming it can be used with ‘standard weapons – just switch the ammo’.
The particular bullets being tested by the US military – DSG’s .50 caliber CAV-X bullets – are suitable for use in partial or fully submerged weapons, regardless of whether the target is in water or on the surface, the company says.
According to Business Insider, they are being tested by the Office of the Secretary of Defense’s Combating Terrorism Technical Support Office (CTTSO), which plans and synchronises operations against terrorist networks.
Among other things, the US military will be testing how well the bullets travel when fired from underwater upwards towards the surface.
DSG is also selling to other governments around the world, the company’s chief science officer Odd Leonhardsen told Defense One – some of which are testing how well the bullets perform when fired from helicopters into the water.
WHY GUNS DON’T FIRE PROPERLY UNDERWATER
Physicist Andreas Wahl wanted to see what happens when a gun is shot off underwater and used himself as the test subject.
Although the gun worked just like it would on the surface, the bullet sank before hitting the halfway point due to the intense resistance in the water.
The bullet casing is waterproof, so when it collides with the firing pin it causes the gun to ignite, regardless if it is underwater.
But water is 800 times denser than air, which hinders the bullet from traveling far and fast.
Compared to air, water has more resistance and holds the bullet back from doing any damage.
When the bullet comes speeding out of the gun it has the same power as it would on land, but with the intense resistance it lost momentum and sank to the bottom of the pool.