And i´m actually having problems with filling up all the weapon slots in the beast..
But the big issue is if its optimal to mix weapons on the same turret och should you not mix because of speed, firerate etc. with the different lasers..
BTW, noticed that if you on other ships mixing lasers on your main guns (not turrets) made it much harder to hit.. (yes i´m using the mk2 fight software and its ENABLED = on)
It will allways be the case that if you mix weapons on your main armament you will miss as often as you hit. The system only allows for 1 max range, speed ect. You will only hit with both weapons at knife fighting range.
As for the other turrets just leave some bays empty. You could consider putting heavy weapons down one side and anti fighter weapons everywhere else as one way to fill the gaps
Ok, as i thought.. I wrote this in another forum and i guess it makes sence with your answere.
"Even though that i´m firing on a moving target and the lasers have different "projectile" speeds (i know that a laser is NOT a projectile but i need to try to discribe it somehow with my limited english)?
In normal fysics the slower projectile needs to be fired earlier to hit the same target compared to the faster projectile..
For example: mixing HEPT and Pased Repeater Gun.
The HPT has a "projectile" speed of 431m/s and the PRG "projectile" has a speed of 1560m/s so the PRG will reach its target earlier than the HEPT.
And that means that one of the laser will miss if the other one hits.
The AI will compensate for different bullet speeds and you will see different bullet types in main battery or turrets going to the target by different paths. The only real determinant for weapon choice is range as the turret or main battery indicator will show in range (or if AI controlled will open fire) for all barrels at the range of the longest reach weapon, thus possibly wasting energy or ammo for shorter range weapons.
There is a benefit in having some range difference though. An AI turret will not begin to turn toward the target until it is in range. That means that for the longer range weapon some firing time is wasted while it turns. If that turret has say one long range and the rest medium range weapons, it will start to turn at the longer range and may be on target by the time the majority medium weapons are in range so they are at maximum effectiveness. This can be especially good with lower laser energy ships where an all big guns loadout would soon run out of energy.
The theme then is that you can mix weapons effectively so long as you don't overdo the range differences, and while some range difference may be even better than none in AI turrets.
I often mix HEPT/PRG/Flak, also IPG/CIG, and also mix IBL/IC and the odd PPC in main/side turrets. Seems to work just great!
if ur piloting it urself, u can use difrent weps with a slightly higer rate of sucsess than the AI, but it generaly just eats energy, withouth even beeing in rage of the target, efectivly rendering the ship unable to hit anything.
ship? what ship? i see no ship? WHO SPAWNED THAT DESTROYER!!!!!
I have had success mixing ISR and Flaks or CIGs in turrets, as have some other posters. I have not noticed the flaks firing at long range, but I haven't specifically payed attention.
I mix HEPTs and PACs occasionally in main batteries or turret as well.
The weapons aim independently for each gun. Obviously large difference in projectile speed will result in some misses against agile fighters that change direction when the faster gun hits them, but combining a faster and slower (and more damaging) gun in a turret can give it the flexibility to deal equally well with larger vs. smaller fighters I believe.
Firstly because when ur firing it, it looks like a tracer round
Secondly it makes the FLAK hit slightly earlier as their max range isnt actaully the "max range" - I hear anyway... however, after hearing something about cluster FLAKs being effective in 2.5 i might put in a few of those instead...
I've not tried alot in X3TC, but I did in X2 and X3R.
I found it often a good idea, and I had success mixing and/or playing with ION / HEPT for example. Anyway, there is a thing to absolutely avoid:
mixing a gun that has an impact effetc with anything other.
Indeed, when it makes the target change direction, all the other bolts (including the rest of the same gun round) fail.
however, after hearing something about cluster FLAKs being effective in 2.5 i might put in a few of those instead... 
