Just about every round fired from a British Army rifle comes from a BAE Systems factory in Cheshire, which makes around one million every day.
The company has a £2.4bn contract with the Ministry of Defence (MOD) to provide all its munitions for the next 13 years.
It also supplies much of NATO, and the cartridges are delivered as far away as India and Australia.
Forces News' Hannah King was given a tour of the facility in Radway Green, finding out how the rounds are made, what innovations are around the corner and what happens if suddenly more are needed.
George Schofield, delivery manager for Light Munitions, told Forces News: "When you look at a round of ammunition, it looks fairly simple.
"When you make up to a million of them a day – to get that right every single time at the rate that we manufacture is a real challenge.
"It's absolutely critical that what we do here is exactly right so that when it's used by the user in defence, we know it will deliver, and they know it will deliver," he added.
BAE is constantly looking for ways to develop its products and innovate.
Site Chief Engineer Martin Clowes said: "We've looked at different design principles and different materials, we're also bringing new technology into those rounds, both in terms of digital technology but also manufacturing technology as well.
"For us, it's quite a step forward in terms of what we do here on site and the capability we then develop."