The newest version of the British Army's standard issue rifle, once dubbed the "civil servant" for its notoriously poor performance, has been hailed as one of the world's "most lethal" weapons.

The SA80, named as it was known as the "small arms system of the 1980s", has been plagued by problems since it was introduced to British forces in 1987.

Soldiers deployed to the Gulf War in 1991 complained the rifle was ill-equipped to cope in sandy conditions across the Middle East, which often resulted in weapons jamming in the heat of battle.

The SA80 was ridiculed to such an extent it was nicknamed in military circles as the "civil servant" with soldiers quipping, "it didn't work and you couldn't fire it".

German defence manufacturers Heckler & Koch upgraded the assault weapon in the early 2000s but soldiers continued to find faults with the modified version during extreme conditions in Sierra Leone and Afghanistan.