This is a rough hack on top of my old CustomLOS example, but here is a Visible Beam that runs fairly quick https://dl.dropboxusercontent.com/u/471 ... eBeam.capx
The red LOSCheck object is much wider than the visible beam, so maybe decrease the height of the LOSCheck for the visible beam to look more accurate!
For more optimizing you could also do this:
Instead of checking every X milliseconds maybe do a function or sub-event that runs when the map has changed/moved that has each BadGuy object spawn a single check bullet.
However, the spawning of more bullets does help though if you want to increase the speed bullets travel at, since sometimes they will miss a collision in their movement. Increasing bullet size helps combat the missed collisions. I don't remember but I thought the C2 Rain demo had a laser that simulates instant-hit as well, or maybe I'm again remembering a CC example.