Nammo has modernized a major innovation, 30mm supercavitating bullets (aka: shells, rounds, ammunition). These armor-piercing bullets could be fired from a helicopter, UAV-helicopter, small ship, patrol boat, land vehicle, water surface unmanned vehicle or LDUUV. They could be used against, mini or larger submarines, mines, incoming torpedos, boats-small ships, against other UUVs and tragically against divers.
These bullets, when fired by a LDUUV, would be much cheaper and multipe-use than if the LDUUV fired mini-torpedoes or itself exploded as a torpedo.
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From the 2018 Nammo BulletIN article
https://www.nammo.com/globalassets/pdfs/bulletin/nammo-bulletin-2018_screen.pdf[PDF 3.2MB]
"While traditional ammunition is either stopped or deflected when it hits water, Nammo’s 30 mm Swimmer (APFSDS-T MK 258 Mod 1) swims straight through water, thanks to a groundbreaking design on the supercavitating projectile developed in cooperation with the US Navy [with USN developing similar 30mm bullets since 1994]. Jan Hasslid discusses the implications of this new technology" [page 8]
These bullets, when fired by a LDUUV, would be much cheaper and multipe-use than if the LDUUV fired mini-torpedoes or itself exploded as a torpedo.
Above is the 30mm Nammo supercavitating bullet penetrating the water.
(Artwork 2018 Nammo BulletINpage 8)
(Artwork 2018 Nammo BulletINpage 8)
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11 seconds into this DSG Technology Youtube ("Norwegian Company" DSG presumably related to Norway's Nammo (?)) displays its 5.56mm and larger supercavitating bullets. Graphics about submarine use. Mention of use against submarine at end (2 minutes 55 seconds).
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https://www.nammo.com/globalassets/pdfs/bulletin/nammo-bulletin-2018_screen.pdf[PDF 3.2MB]
"While traditional ammunition is either stopped or deflected when it hits water, Nammo’s 30 mm Swimmer (APFSDS-T MK 258 Mod 1) swims straight through water, thanks to a groundbreaking design on the supercavitating projectile developed in cooperation with the US Navy [with USN developing similar 30mm bullets since 1994]. Jan Hasslid discusses the implications of this new technology" [page 8]
"...Nammo, through its Strategic Alliance Agreement (SAA) with General Dynamics Ordnance and Tactical Systems (GD-OTS), [became] one of the main providers of 30 mm ammunition for the US Armed Forces. [page 8]
Following the recent signature of agreements with the US Army and the US Navy, both services are now adopting Nammo’s 30 mm APFSDS-T MK 258 Mod 1, or “Swimmer”, for use from a multitude of platforms,..." [page 8].
"...The Swimmer round falls into the category of sub-caliber kinetic energy penetrators. These can most easily be described as arrows made out of very heavy materials that use the force of the impact rather than explosives to punch through armor. Traveling at speeds of more than 1 km per second, the energy generated by the impact melts the armor of the vehicle into a fluid and the arrow “swims” through the armored side of the vehicle. In the case of the Swimmer, the force of the arrow is sufficient to defeat anything except main battle tanks [so could penetrate a single or even double hull submarine] ..." [page 9]
"...What makes the Swimmer unique, however, is the combination of powerful armor penetration and its ability to swim straight through water. This effect has until now been considered impossible to achieve by ammunition fired from air through water. As demonstrated by a number of popular science TV programs, traditional ammunition is either stopped or deflected when it hits water. In a worst case scenario, a projectile could hit the surface, bounce off [richochet] and hit something else.
Thanks to the design effort for the kinetic energy penetrator originally developed for the Norwegian Army, and perfected by Nammo in combination with US Navy supercavitation [the bullet's shape of nose which may shake allowing bullet to fly through a gas bubble] concepts, the Swimmer avoids the ricochet in water problem through the use of a supercavitation nose design. This means that the projectile creates a bubble of steam around itself big enough to pass through, substantially reducing the friction
[article ends on page 9].