@Wraithblade6 That one actually has real-world science backing it up. Ork are, largely, fungus, i.e. plants. Studies into the topic have shown that plants can survive in a vacuum for upwards of thirty minutes without negative consequences. Now, being only mostly fungus, it still likely wouldn't agree with him. However, again going back to the ork thing, he'd shake off what damage was caused pretty quickly.
@Klomster It's less a matter of him not being able to figure it out, so much as he has no reason to. Remember, Urgrugg thinks largely like a human in many ways. Given time and motive, sure, he'd probably be able to figure out which of the available weapons are guns, and would pull their triggers until he found one that did as he needed.
However, keep in mind, he comes from a feral world. His experience with technology has been limited by what the rogue traders who hired him allowed him to see and interact with. Given what they were, most of them wouldn't have access to the kind of weaponry you'd see on a space marine ship. The few that did especially wouldn't be packing around the same model as a founding chapter from before the heresy.
Basically, what it comes down to is, he doesn't know what any of the guns do because he's never seen them before. He knows what a gun is, and has the basic understanding of how to operate it (point, pull trigger, etc.) but that's not the first solution he'd ever turn to. In this case, he's passively assuming that if any of the weapons on the ship Could help them, then one of the four people on the ship with experience with those weapons would have already picked it up and would be using it. That, or there's some reason why they haven't yet.
I'm not saying he wouldn't ever have the idea; I'm saying he'd dismiss it as not being a good one.
