Okay the first first things first. The difference between the m-4 and the m-16 is that the M-4 has a shorter barrel, an ex-stendable and re-tracktable stock, can have better grip, has better accuracy than the m-16, can have more equipment on it (optics, sling, etc...), better for CQC (close quaters combat) because of its size and because of that its perfect for urban and indoor combat, its light and easy to carry. But the M-4 has its flaw because of it's short barrel its range is decreased. The M-16 is a pretty good weapon beacuse of the barrel the range is incresed, it can do all the same as the M-4 but it is less effective at CQC, and its heavy and big. The M-4 is used by specs, assault, etc.., the M-16 is used by drivers, pilots, and medics.
The C-8 is the same as the M-4 but is the Canadian version ( the C means candaian).
Now the Berretta; the Berretta is a pretty good handgun but it has alot of important flaws. The first one is the the Berretta tends to jam in inappropriate times during combat, it has a small catridge and the cartridge hardly goes in, the cartridge rejecter button hardly works, the trigger handle is to small and there's hardly any grip to cok the weapon.
