This is a piece I should have posted earlier this month but as advanced weapons development is being discussed it fits now:
Navy Quietly Fires 20 Hyper Velocity Projectiles Through Destroyer’s Deckgun
Guided-missile destroyer USS Dewey (DDG-105) transits the Pacific Ocean while underway in the U.S. 3rd Fleet area of operations. US Navy Photo
Last summer USS Dewey (DDG-105) fired 20 hyper velocity projectiles (HVP) from a standard Mk 45 5-inch deck gun in a quiet experiment that’s set to add new utility to the weapon found on almost every U.S. warship, officials familiar with the test have told USNI News.
The test, conducted by the Navy and the Pentagon’s Strategic Capabilities Office as part of the Rim of the Pacific (RIMPAC) 2018 international exercise, was part of a series of studies to prove the Navy could turn the more than 40-year-old deck gun design into an effective and low-cost weapon against cruise missiles and larger unmanned aerial vehicles.
While the HVP was originally designed to be the projectile for the electromagnetic railgun, the Navy and the Pentagon see the potential for a new missile defense weapon that can launch a guided round at near-hypersonic speeds.
Currently, the fleet uses a combination of missiles – like the Evolved Seasparrow Missile, the Rolling Airframe Missile and the Standard Missile 2 – to ward off cruise missile threats. The missiles are effective but also expensive, Bryan Clark with the Center for Strategic and Budgetary Assessments told USNI News on Monday.
In 2016, guided-missile destroyer USS Mason (DDG-87) fired three missiles to ward off two suspected Iranian cruise missiles fired from Houthi rebels in the Red Sea, in what amounted to a multi-million dollar engagement.
An artist’s conception of BAE Systems’ Hyper Velocity Projectile. BAE Systems Image
“So if you think about the kinds of threats you might face in the Middle East, the lower-end cruise missiles or a larger UAV, now you have a way to shoot them down that doesn’t require you use a $2 million ESSM or $1 million RAM because a hyper velocity projectile – even in the highest-end estimates have it in the $75,000 to $100,000 range, and that’s for the fanciest version of it with an onboard seeker,” he said.
An added benefit of using HVP in powder guns is the gun’s high rate of fire and a large magazine capacity.
“You can get 15 rounds a minute for an air defense mission as well as a surface-to-surface mission,” Clark said. “That adds significant missile defense capacity when you think that each of those might be replacing a ESSM or a RAM missile. They’re a lot less expensive.”
A range of hyper velocity projectiles from different weapon systems. BAE Systems Image
Just the 5-inch version of the HVP could be a major upgrade for ships equipped with this gun and its cheap enough to defeat British Treasury objections, though I don't think it would receive such objections when it would let them buy fewer missiles instead. Canada and any other NATOnation using such guns could also benefit, as could Australia and Japan. And 155mm version could significant alter the artillery imbalance in NATO's favor.
(Note that the second image came from the BAE Systems page on the HVP, as the image on the USNI page was coming through distorted.)
Edited by Dark_Falcon, 20 January 2019 - 1150 AM.