Statting 4e Weapons & Vehicles

[Heffe]

I think 5 probably works as well from a balancing perspective. Since we already know that it's not only the cyclic rate that is taken into account when determining the ROF (as per the aforementioned M16A2), then we can find other reasons why the MG3 should only be 5 instead of the full six in order to justify the balance. Maybe PCs firing the MG3 have to worry about additional heat build up on it due to the higher firing rate, and therefore are trained to fire it in shorter bursts?