Hello everyone !
As stated in my introduction post (see the "tranlastion" topic), I am deeply interested in weapons, military and tactics.
And as such, I have noticed that the already quite comprehensive UFO:AI armory lacks one major piece of equipment that has been found in every infantry formation since WW1 : a light or general purpose machine gun, comparable to the FN Minimi (M249 in the US army), M60, or WW2 german MG42 (but NOT Gatling gun !!!).
Such weapon would be capable of fast automatic fire, with a greater range and damage than the assault rifle (but not too much : they still use the same ammo in real life. +10-30% seems fine.), be belt-fed (100-250 rounds), but heavier than other shoulder weapons.
They may or may not be able to fire single shots, take more time to reload (and maybe fire as well), and, ideally, would take rather major penalities if fired while standing instead of crouching (or being prone if such feature gets in game in the future).
Skill used would of course be heavy weapons.