Light Machine Gun
used to mean:
7.62mm conversion of the Bren gun. Redesignated as the L4 series.
A useful and less cumbersome option than the GPMG in the section weapon role, the LMG was limited by magazine capacity but compensated for this in great accuracy. The introduction of the 5.56mm LSW rendered the weapon obsolete and the few that were left in second line service have now been replaced.
A 5.56mm machine gun with a choice of magazine or belt feed. Bought as UOR but coming in to the rest of the army eventually. Often referred to as the 'minimi'.
Basically when the SA80 system was conceived the powers that be decided that the infantry section only needed a support weapon that was magazine fed. The idea being that the old bren was good enough in WW2 and accuracy and not rate of fire was what was important. The fact that the rest of the world was busy arming it's soldiers with underslung grenade launchers and 5.56 machine guns in their infantry sections mattered to them not a jot.
They were fucktards, can't be helped. Once the Army actually started doing some fighting the incredible imbecility of this approach was realised, an off the shelf weapon was aquired and everyone was happy