In all honesty, the only thing that needs to be altered in terms of the weapons both primary and secondary is different damage archetypes for the different types of guns. For example, the highest fire rate of weapons with high control are preferred at the moment due to their lower time to kill and their range is the same as other rifles of the same class. There should be a greater damage drop-off for these weapons similar to how Call of Duty handles the difference between Assault rifles, Sub-Machine Guns, and Light-Machine Guns. The larger, slower firing weapons should deal the same damage to kill at mid range as every other weapon, but their damage drop-off should be far less. The fastest fire rate weapons should have the same time to kill in close-low mid range scuffles, but lose out hard in longer range engagements. As for the middle ground weapons, they should be great at a mid range, but then be ok at a close or long range firefight.