(Translated by https://www.hiragana.jp/)
Light support weapon - British Army Website
The Wayback Machine - https://web.archive.org/web/20151210175443/http://www.army.mod.uk:80/equipment/23231.aspx

Light support weapon (LSW)

SA80 A2 light support weapon (LSW) has a heavier and longer barrel than the SA80 individual weapon allowing greater muzzle velocity and accuracy.

When fired from the integrated bipod and using the standard SUSAT sight, the LSW is accurate and consistent. It can fire 610 to 775 rounds per minute out to a range of 1000metres.

Calibre: 5.56mm
Weight: 6.58kg (with loaded magazine and optical sight)
Length: 900mm
Barrel length: 646mm
Muzzle velocity: 970m/s
Feed: 30-round magazine
Effective range: 1000m
Cyclic rate of fire: 610 to 775 rounds per minute