I co-developed a modern skirmish system with another guy in my Regiment several years ago (Presently the CO of that Regiment).
We used 1/72 scale and the ranges involved were all based on the real effective ranges of the weapon systems. We used a big f'n table. No where was technicallly 'out of range' for an assault rifle, let alone a machine gun.
In that system we had a Beaten Zone template for the machine guns. It was of course based on the shape of actual beaten zones according to the military publications. There was one for the LMG, one for the GPMG, one for the HMG and even one for chainguns and light automatic cannon.
When it came time to fire one of these fully automatic weapons, you just placed the template, cut out of clear film, onto the table and oriented it properly based on the position of the gun. It had a minimum range from the gun, not a maximum that it could be placed, because it takes distance to get the round dispersion. Firing closer than 100m or so and you just treat it like you are firing at a point target.
Whatever figure was under the template got attacked with the gun.
If you gave the gunner an order chit for maximum fire, then you got to lay the template twice. You could lay it end to end to make the beaten zone long and thin, or you could lay it side by side to make it shorter and wider. You could even just keep it in the same spot and attack everyone in the zone twice rather than once.
If you spent the time to 'dig in' you could have your weapon in the sustained fire mode, which allowed you to lay the template 3 times. Again, end to end, side to side or overlapping.
I don't recall if we had suppression per se, as in LoS or Planetstorm. I'd have to go over it again to find out, but I believe that it was more of a covering-type system. If you go out into that area, where the gunner has oriented himself to face, then said gunner gets to shoot first.
Just food for thought to mine for ideas.