Fun little conversation Sigg and Lionel, mind if I jump in with my 2 creds?

yeah, like I'd give you a choice
Oops, hey no slight intended LordRhys
I think you have it about right, if I follow you correctly (but I'm not quite up to giving you the math, not when a picture might do
)
Unfortunately "they" keep changing the url. Fortunately it's a simple graphic and the description is (probably) good enough without it.
So... Imagine two targeting circles (because they are from the gunner's perspective). The cones (in actuality) extend from the laser (point) to the target's maximum plotted range (x, y, and z, with only x and y being visible, z being a factor only in the limit on x and y since it could extend infinitely, but is effectively only several hundred-thousand (?) kilometers at most for damage). The target vessel will be a point at this scale for any range much beyond visual.
The beam laser of energy value 1 (for example) traces it's hit across the whole area (yes actually a 3d cone but effectively a circle so area works fine) as a series of lines. It scans the whole target circle (hence the long space combat turns) to attempt a hit. The tighter the circle the closer the lines and the more likely a hit will occur). The energy value of 1 is divided across the whole scan.
The pulse laser on the other hand targets the same area with a series of distinct points (pulses) which lowers the overall chance of hitting, but because the same energy value (of 1 for example) as the beam laser (to compare) is divided fewer times to cover the same area any hit will do more damage.
This is about the way I see it working anyway (simplistically at least). It does of course raise a couple of issues (at least).
One that always bugged me was the old CT "Selective" program that let you choose the area of the ship to target. No doubt inspired by ST where all combat seems to take place at visual range. Most of the ranges assumed in Traveller are well beyond visual and I don't allow selective targeting. I might allow it at visual range or for certain cases (i.e. a fleeing ship is likely to be presenting nothing but engineering, while one coming hard at you would probably not give you a shot at engineering).
Another is that you might argue that any laser could be selectively beam or pulse. A nice bit of versatility which might be a good idea, probably at a slight cost increase, say maybe Mcr1.25 in CT, or if you're feeling generous allow beam lasers to fire in pulse mode but not allow the cheaper pulse lasers to fire in beam mode.
And one more before I yield the floor, it might be possible with this model of events to actually hit something else straying into your field of fire, if for example there are more than one target in the same potential area. There should probably be something to cover that possibility.
Anyway just some thoughts from my wandering mind.