Probably ABS I'd have thought for a gun. ABS deformed plastically further than polycarbonate, I assume. Polycarbonate goes quite a long way before it fails, but when it fails it tends to shatter. Last time I checked, they used ABS in riot shields for its handling characteristics. Maybe they're using blended ABS+poly these days though, I'm probably out of touch with that stuff.
As far as I've been paying attention, they're still using polycarbonate for all of the current Pyra case tests, including the ones with inclusions. I can imagine using a blend of materials might make getting just the right colour a little more tricky.