LMG's are rather pathetic they server no good role.
The fact they can over heat as well as don't become accurate till you have fired about 5 to 10 rounds leaves you a small window where you can accurately hit a target.. but by then your target is going to move.. they have no effective range where they are not out classed.. the current suppression system is totally worthless.
Things I think that would help.. I'm not saying added all the them.. but one of them would help the current lack of role of support LMG's
1: up the bullet damage.. 21 is just way to low. upping it to mid to high 30's would be a better point to have the damage.. as LMG's already have to waste many shots to get there guns to become accurate.
2: fall off damage.. make the fall off damage more in line with sniper rifles.. this would mean that there pathetically low damage at least will remain consistent at long range.. after all they are firing rifle rounds...
3: If your going to keep LMG's with pathetic accuracy, overheating and weak damage.. then put in the blurring vision effect from suppression for LMG's.. and only LMG's. I feel that BF3 suppression system for LMG's was by far the best as it gave a reason to have high magazine/belt fed. That the blurring effect made covering fire with a LMG worth doing.. right now you can pretty much ignore a LMG player at range as its suppression means squat.. and the blurring made it effective tool to cover the movements of assault and medics rushing.. the core of what covering fire should be used for.. but this should be a LMG only effect.. unlike BF3 where all guns got the effect.. I feel only LMGs should have it.
Right now support doesn't feel very supportive.. other then for a few sec where you slap out a mortar to support your attackers.