The US Army is turning toward their existing heavy artillery guns to shoot down ballistic missiles as the threat of enemy missiles gets more real by the day.

The Pentagon has reportedly turned to a project to build what is called a Hyper Velocity Projectile (HVP) that can be fired from existing field artillery guns to take down ballistic missiles. These projectiles will be fired from heavy howitzers and the Navy's deck guns at incoming ballistic missiles.

Defence systems that are designed to take down incoming ballistic missiles are not only expensive, but also cannot be expected to work with 100% accuracy, every time, notes Popular Mechanics. This means, every target will need multiple defensive missiles protecting one target. Considering how much each defensive missile costs, Popular Mechanics reports that more money will eventually be spent on raising these units and destroying targets than the cost of the incoming ballistic threat.

As of now, the US has a number of ballistic missile defence units such as the Patriot PAC-3 MSE, THAAD, and Standard missiles, notes the report, but each of them cost over $2m (£1.41m) a missile and multiple missiles will be needed to counter each target. This will drive up costs fast.

Right now, the armed forces have large guns like the M777 155mm and the M109A6 Paladin that can shoot high velocity, explosive, smoke, and like shells to distances of over 18 miles, says the report. Researchers from the Pentagon have now decided to equip these guns to fire HVPs- projectiles that can travel at speeds of over 5,600 mph. These will cost only $86,000 a shot.

While a Howitzer firing a HVP is likely to have a lower kill probability than a patriot missile, for instance, the advantage of using guns is the chance of firing multiple rounds in quick succession. A typical six-to-eight-gun field artillery battery is capable of firing up to 24 rounds in under 15 seconds, notes Popular Mechanics.

The Navy also has large 5-inch guns aboard their destroyers and cruisers, which can also be transformed into HVP-capable units, reports the website. Now that the rail gun project has reportedly been abandoned, they are also in search of a new high velocity projectile to arm their ships with even if the HVP is not likely to have the range of the now-cancelled long range land attack projectile.

The US reportedly faces a host of ballistic missile threats from land as well as the sea with Russia's Iskander class missiles being developed, the Chinese building their own DF-21, and North Korea's Nodong missiles.