It is an interesting idea, Dave. I considered the same thing for my Hummel, since it has no machine gun mounted in the hull, but I could not find a small enough drill bit for the MG that I have.

If you get the hole drilled and the optical fiber inserted, I guess you are home free. You could even use the insulation from a wire (experiment with different gages, I guess) over the fiber, so that it would only flash at the end of the muzzle.

I'm looking forward to seeing the results....................so I can copy.

Good Luck!
Jason