[Campeador]

What you ask is very easy to do; this is what I did to see how it works:
On the 'Components.txt' I changed this fields on the "Point Defense Cannons":

Energy Consumption := 15
Weapon Damage Point Blank := 10 (20 points of damage)
Weapon Reload Rate MS := 1500
Weapon Display Effect Name := Bolt 3
(I will not change the range (distance) for this test)

to this:
Energy Consumption := 1.5 (this is amost = 0)
Weapon Damage Point Blank := 1 (2 points of damage)
Weapon Reload Rate MS := 150
Weapon Display Effect Name := Fast PDF (I just created a new name)

on the 'BitmatEffects.txt'
Speed := 1.2
to:
Speed := 12

All this will make the Point Defense Cannons fire at 10 times faster rate, causing 2 points of damage instead of the present 20.

How it works once implemented on the game:
Realistic factor:
You get the desired machine gun effect.
They may miss 10 times less, since they go 10 times faster.
The damage resistance of a torpedo or missile is 5 ("Weapon Tonnage Structure := 5"), that means that before it was destroyed with one hit (20 vs. 5), now it will require 3 hits (3 hits 2 points/each vs. 5)....good or bad I do not know, but over all seems to have the same results as the original (on the slow torpedoes/missiles).

Fun un-realistic factor (In my opinion (based only on 10 min of play)):
They go really fast, you can hear them, but can barely see them.
Yes, more realistic, but the original slow rate of fire seems to match better the slow speed of torpedoes and missiles.
Not sure against fighters...fighters may have a better chance of survival if they keep moving fast out of the way.
All the fighters on the game are much bigger than the scale of the other ships. If they were the right proportional scale, they would be really hard to see (no fun, IMO), but at the same time even harder to hit (not so bad!)

Will I use this on my next mod?...I do not know, I like the possibility of fighters lasting longer, but on every hit there is sound, and a little graphic effect on the hit that goes 10 times more than before, which in turn will be more graphic intense on the computer, may tend to slow down things a bit and I like to have a lot of ships on the screen.

I hope that this helps; you can play with the settings to make it as you wish. By the way the new mod I am working on will have a lot of variations on weapons, some look very impressive, all by the end of summer (I hope!)