From personal experiance, I can comment on 1 machine gun-
The LSW, which i first fired a year ago -
www.army.mod.uk...
This is the smallest support weapon in service with the british army, and is amazingly reliable (especially compaired to the SA-80). The only problems
with it are the small magazine (30 rounds) and the limited range (about 800m maximum, although i was taught it could fire to about 1000m, it can't
accuratly). The thing i like about it is the accuracy, and the light wieght, especially compaired to the GPMG.
(just incase anyone is wondering, I fired the LSW in the cadets about a year ago)