The Bullet That Swims Few things are more effective at stopping a bullet than water. Except this one - the Swimmer goes straight through. RESOURCES THORSTEIN KORSVOLD, 20 May, 2020 Nammo’s Swimmer bullet is the result of a unique cooperation between Nammo and the US Navy. A concept that combines armor piercing with the ability to shoot straight through water is being rolled out in significant numbers, for the first time. Jan Hasslid, one of Nammo’s lead engineers on the project, explains how the Swimmer started out as an armor piercing ammunition. – The original Mk258, (the predecessor to the “Swimmer”), was designed for use with the Norwegian army’s combat vehicle, the CV90. Test results were really good when the ammo was fired from their 30mm Bushmaster cannons – we could defeat armored vehicles at a distance of 4000 m, Hasslid says. But when the US Navy started looking at the ammunition, they saw even more potential. JAN HASSLID US Navy engineers had an idea about shooting straight under water, and with the robustness and performance of the new Mk258 ammunition we found out that the impossible was actually possible. – We worked with US Navy engineers to qualify the Mk258 for use with USMC amphibious vehicles. US Navy engineers had an idea about shooting straight under water, and with the robustness and performance of the new Mk258 ammunition we found out that the impossible was actually possible, Hasslid explains. Under the right circumstances, a bullet can create a bubble as it goes through water. This leads to an effect known as super cavitation, where low pressure behind the bullet reduces drag drastically. But getting there is a daunting technological challenge. It means creating massive pressure at the tip, enough to lower pressure behind it (using the venturi effect), which in turn transforms the water there into vapor. – We already had something that we knew worked well against armored targets. In addition, our engineers utilized the latest of materials technology, hydrocode simulation tools, as well as Computerized Fluid Dynamics, CFD, to maximize performance of the new design. It took a lot of effort, but we got it to work, Hasslid says. In addition to just being effective against its intended targets, the main advantage of the Swimmer is versatility. Having just one ammunition type that works against multiple target types – instead of several that need to be changed – makes units more effective in battle. It also helps the logistics chain. JAN HASSLID I’m also very optimistic about what we can counter with this: torpedoes, mines or even submarines could all be within range. Both the US Army and the US Navy are now using the Swimmer. In addition to the new capabilities, that also means less switching between ammunition types. The implication is pretty straightforward: Submarines, torpedoes or other underwater systems become more vulnerable. Instead of using expensive and specialized counters, defenders can now simply fire at such threats, with the guns they have. – The interest in the Mk258 is tremendous, and it is now being fielded with the most modern weapon systems for US Army and US Navy. I’m also very optimistic about what we can counter with this: torpedoes, mines or even submarines could all be within range, Hasslid concludes. TAGS 30 mm x 173 APFSDS-T 30mm armor piercing Bushmaster Jan Hasslid medium caliber Nammo super cavitation US Navy ABOUT THE AUTHOR THORSTEIN KORSVOLD YOU MIGHT ALSO BE INTERESTED IN Celebrating 125 years at Raufoss Raufoss has become one of Norway's most import industrial hubs. In 2022, the industrial park celebrates 125 years. Drone-mounted M72 shows promising results 12 Nov 21 - Nammo has for several years been working on a concept where the M72 is mounted on… NORWAY NAMMO AS MAIL P.O. Box 142, NO-2831 Raufoss, Norway VISIT Enggata 40, NO-2830 Raufoss, Norway EMAIL info@nammo.com TEL +47 61 15 36 00 (0800 - 1530) About us Careers Finance Board of Directors Locations Management Newsroom Our Responsibility Suppliers Products and Services Ammunition Commercial Brands Demilitarization Propulsion Shoulder Fired Systems Space Copyright © 2021 Nammo AS | Privacy Policy | Register of Business Enterprises: NO 979 984 731 MVA Nammo retains all rights to this website and the contents published here, except where explicitly stated otherwise. Content, designs and data on the website are protected pursuant to the Copyright Act and other legislation. Rights to all product and company names, logos and trademarks on the website are owned by Nammo. Content may not be altered, reproduced, published, distributed or in other respects used for public or commercial purposes without permission. We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.I am happy with itOur Privacy policy