Weapons undergo dynamic stresses throughout their service lives, so it is crucial that a weapon remain safe and reliable to use. The question is therefore, how can dependability and safety be measured? This is where testing and verification come into play as vital parts of the design and quality assurance process.
FN Herstal is a company that understands the importance of weapon testing. Rather than only rely on computer or theoretical calculations, its weapons undergo rigorous examinations to ensure they meet everything asked of them. Only testing under realistic conditions can measure a weapon’s performance and reliability.
Different test cycles are used for weapon development and qualification. Testing accompanies every part of the design process, as it may reveal issues requiring design modifications. Before any weapon reaches series production, it is tested to breaking point. Comprehensive documentation and data are accumulated from tests along this journey towards industrialisation, proof for both the manufacturer and client that their weapon fits the bill.
On the other hand, validation tests focus on meeting required standards. They determine the lifespan of a weapon and how it will perform. Qualification of new weapons typically takes around four months, and it contributes to the final technical specifications communicated to clients, so that these customers can be fully confident their equipment will operate reliably in every condition.
In-house testing
FN Herstal runs its own Test Centre, which holds EN 9100 certification, in order to maintain the highest standards. Typically, every year it hosts around 130 test campaigns and up to 400,000 cartridges are expended.
Having this Test Centre – along with the associated human resources and expertise – means project teams are closely connected to their product and can appropriately respond to modifications desired by clients.
Because weapons can be adapted to meet customer requirements, the Test Centre verifies they are fit for purpose. Interestingly, FN Herstal tests products under client supervision too. This approach has led to contracts, such as when the US Special Operations Command qualified the FN SCAR in 2005.
There are eight firing tunnels, ranging from 5m to 50m long, located in Herstal, while six firing ranges at Zutendaal measure from 0 up to 1,700m. Furthermore, there are four climatic chambers that control humidity and enable extreme-temperature testing. Zutendaal’s chamber offers the most extreme conditions, with temperature ranges of -60°C to +85°C. Even a remote-controlled weapon station can be placed inside the chamber and tested under the most adverse conditions. Few companies possess such a capability.
Once a weapon meets desired performance levels, it proceeds to a series of tests under various standards, one of the most important being NATO STANAG AC/225 D/14, commonly referred to as “D/14”. FN Herstal Infantry test protocols are based on D/14 to ensure compliance with international standards, but the company even goes beyond those since it sets its own standards even higher.
Proving their worth
The Test Centre fulfils four roles: operational, instrumentation/mechanical simulation, ballistics and Systems environmental test engineer.
Operational technicians are at the beginning to test prototype weapons, firing thousands of rounds, and providing valuable feedback to designers.
Safety tests for new weapons include drop safety, or ammunition cook-off testing when barrels are hot. Environmental tests involve sand and mud, cold and heat, humidity and rain, salt and frost. Also, shock and vibration resistance tests recreate conditions experienced in vehicles, ships or aircraft.
Endurance firing involves tens of thousands of rounds from 9mm to .50-cal.
Technicians may train for several years in the Test Centre, and this experience is invaluable if they transition to other roles within the company.
Environmental tests involve sand and mud, cold and heat, humidity and rain, salt and frost. Also, shock and vibration resistance tests recreate conditions experienced in vehicles, ships or aircraft.
With thousands of euros invested in testing equipment annually, the Test Centre has various measurement and mechanical simulation tools available. For example, they can measure weapon kinematics (the displacement and velocity of moving parts relative to the receiver), or assess thermal, visual and sound signatures during operation, as well as recoil forces and acceleration.
Instrumentation at the Test Centre includes pressure sensors, high-frequency cameras, displacement sensors, methods for measuring kinematics, speed radar and pressure transducers, for example. The cameras are phenomenal, as they film 40,000 frames per second in high-definition resolution. Such speeds are necessary to understand ultra-fast weapon cycles of just 70-100 milliseconds.
Instrumentation at the Test Centre includes pressure sensors, high-frequency cameras, displacement sensors, methods for measuring kinematics, speed radar and pressure transducers, for example. The cameras are phenomenal, as they film 40,000 frames per second in high-definition resolution. Such speeds are necessary to understand ultra-fast weapon cycles of just 70-100 milliseconds.
Mechanical simulation – using pneumatic, electric or hydraulic actuators – can mimic weapon actions, and it is so accurate that weapons do not actually have to fire live rounds all the time. For instance, one of FN Herstal’s hydraulic actuators can simulate weapon firing rates as the actuator head strikes moving parts, applying the same force and speeds as real shots do. This high level of simulation saves time and money on ammunition.
The Test Centre also has a ballistics section that studies ammunition in the fields of internal ballistics (pressure), external ballistics (projectile speed and trajectory) and terminal ballistics (effect into steel plates, gelatine, …). This section is very busy and useful in these times of new standards for non-toxic primer or new ammunition programs.
Finally, the Systems test engineer manages the environmental qualification part in compliance with MIL-STD, AECTP or DO160 standards of the System products. He establishes the qualification plan and the related testing procedures, organizes the tests with internal and external laboratories, and summarizes the results in the Qualification Report. The requirements are climatic tests, vibration, EMI/EMC tests (electromagnetic compatibility tests), solar radiations and so on.
With new weapon testing constantly occurring, as well as extensive internal ballistics testing of new “green” primers that are less harmful to the environment and to shooters, there is no let-up in the Test Centre’s busy schedule!