The Warrior has been serving the British Army since the 1980s.
In the past three decades, it has seen service in both Iraq wars, Bosnia, Kosovo and Afghanistan.
Now, the armoured fighting vehicle is undergoing extensive trials in Bovington, Dorset, to test changes to its turret.
The old vehicle is now known as the 'legacy' model, with the upgrades being hailed as "an absolute gamechanger" for the military.
The changes focus mainly on the vehicle's turret and include an increase in the size of the cannon, improved stability and digitisation.
Colonel Howard Pritchard said the goal of the upgrade is for the Army to have "the world's very first infantry fighting vehicle that can fire and hit, with pinpoint accuracy, moving targets whilst on the move".
Plans to redesign the Warrior's turret were first announced in 2011, with hopes it would extend the vehicle's life into the middle of the 21st century.
Defence manufacturer Lockheed Martin was awarded a contract worth £1.3 billion by the Ministry of Defence (MOD) to carry out the upgrade.
The MOD will decide whether to upgrade the whole legacy Warrior fleet, based upon the findings from the trials in Dorset.
Changes have also been made to the chain gun to make it less prone to jamming, as well as improved interchangeable armour.
"It's an absolute game-changer, to be honest, compared to what we had before," said Warrant Officer 2 John McAllister, part of the Armoured Trials and Development Unit that is working alongside Lockheed Martin during the tests.
"We could never fire on the move with the legacy Warrior - now we've got that capability... with a stabilised cannon as well.
"With legacy before, you'd look through your sights and if the driver slammed on his brakes, all you could see was ground and then sky.
"Now, because it's stabilised and the vehicle can be moving, that gun just stays on that target."
As well as being able to fire on the move and having a bigger main cannon, the upgraded Warrior also fires a different kind of ammunition.
"So, we've got HE Airburst [High Explosive Airburst Ammunition] and the better penetrator for the AP [armour piercing] round.
"Inside the turret, the cognitive burden, if you'd like from the commander side, has gone away because all he's got in front of him are the screens.
"He interacts with the screens rather than having to reload every three rounds and think about what's inside the gun like you would do on the RARDEN cannon.
"This one is easier to use and interact with."
However, the programme to upgrade the Warrior has not been without its complications.
In March, the MOD admitted it had "some initial challenges to overcome" with after it was announced the project was delayed and £227 million over budget.
The first of the upgraded vehicles was originally due to come into service next year, however, that is not expected to happen until at least 2023.
"We've got a vehicle design to play with and we're starting to learn all the issues, the snags, the faults that pop up all other the place as we fire and use the vehicle and that's what exactly we're doing here today," said Colonel Howard Pritchard.
"The goal is for us to have the world's very first infantry fighting vehicle that can fire and hit, with pinpoint accuracy, moving targets whilst on the move.
"What that means is the vehicle does not need to stop to fire - that will increase tempo against the enemy and that is something which our potential adversaries and our allies will certainly sit up and notice."