Not that I have anything more to contribute to this discussion as I still think my point remains valid, but...
There is a turret for a fighter that has the fastest weapon speed of all energy based weapons, yes, it's greater than 750 m/s, perhaps you should use it for a model.
The Vengeance Mk III Turret Liberty produces has a range of 680m and its velocity is a staggering 850 m/s. Add your thruster going at 200 m/s and you have a weapon that is flying at 1,050 m/s. If velocity is going to be increased, I'd look at that turret first...