so i want to punch through a window, do i use twice or half the barrier rating?
the book has me confused.

twice. "Punching through" in the game sense is shooting a bullet through a barrier making a small hole and doing very little damage to the barrier. Punching through is essentially breaking through the barrier.

It depends on what you're calculating. If you're punching through and hitting someone on the other side, you use the barrier rating (unmodified by anything) to see how much damage the target on the other side takes.

Then when you go to see how much damage your hole did to the barrier, use twice the rating and compare it to the barrier effect table.

Are you certain that it's twice for melee weapons?

~J

He's sure. He looked at "Breaking Through" on page 125, where it says that "Against melee attacks, a barrier has twice its normal Barrier Rating."