I'm sure this won't settle anything, but it's definately interesting.
A 1200 lb (416 kg) draw crossbow is tried out against a 3mm steel breastplate.
This page is in German but the two links on the bottom of the page are to the videos of this experiment in action. Nice slow motion shots.
From my friend Richard, who sent me this:
"The page also gives info on the equipment used and states that only the hardened triangular bolt entered the plate about two millimeters before the tip broke off. Wow. Obviously, this isn't a statistically significant thing, as there were only two shots made, but still interesting."
http://www.plattnerwerkstatt.de/beschuss.html
Jeanry

