Machineguns would be cool, High ammo use, Maybe no ability to single shot (balance wise) and have them like other weapons, with 5mm, 7.62, 8.6, 9mm, 12.7 in different chassis, use the AR sprite? (as I remember reading ages back that its quite expensive getting new sprites made) and have high weights. Making them practicably the only weapon you can carry without less loot space/armour?