Boarding Actions, weapons, & Ammo

Obviously, when you're engaging in a boarding action, you want to avoid putting holes in the hull. However, it's not as tricky as you think; for lasers, it's just a matter of using the right frequency for the hull material in question, and for slug throwers, it's just a matter of using the right ammo. "Rainbow Lasers" let you pick whatever frequency is best suited to the task, and may even intelligently pick the right frequency for you, depending on your purposes. This means you can pick a frequency of light that harmlessly absorbs into the ship's bulkhead or hull material, or even one that reflects off of it. On the subject of ammo, you should be using " Frangible Ammo " at fully automatic. The short version is, these bullets harmlessly crack apart on stuff like drywall, but penetrate flesh just fine.

Not sure if there's frangible ammo in Traveller, but there is flechette ammo. Same concept really. Good at penetrating flesh but not very good armor penetration.

No, flechette ammo is not even remotely the same thing. When you fire frangible ammo at a pane of glass, the round shatters instead of the glass . Flechettes are thin and narrow for extra penetration, but to get that, they have to be extra hardened, so they don't split apart after breaching the armor... which means they won't mushroom once they get to the fleshy part and do extra damage. Their tiny diameter is critical for penetration, but damage is done better by larger diameter ammo unless you hit something vital . Any divergence from this is due to Traveller's inherent lack of realism; it wouldn't surprise me that they got an entire ammo type wrong. See GURPS High-Tech for details. It's the RPG book every gun nut should have, and has entries on both Frangible rounds and Flechette rounds. Actually, see  this page that Steve Jackson Games made public ; Semi-Armor-Piercing Fin-Stabilized Discarding-Sabot are the only Flechette rounds currently used by small-arms ; anti-tank weapons have plenty of flechette rounds, though.

I want to take the time to remind or inform everyone we have been slowly working towards mongoose to get us all on the same sheet eventually. 

Yes, I know, I was just referencing GURPS for the sake of being informative. Traveller's unrealism really has no place in GURPS's gritty hard-realism. That being said, GURPS's well-researched material can often shed light on how things should be if translated realistically to a game system; the extent to which that is appropriate for a game system that isn't really shooting for realism to begin with is a debate in itself.