Hollywood gun myths: Nice to see a divergence from the usual two-myths-per-episode format, and to see more mini-myths. Although this had so many mini-myths that the result was kind of scattershot, pardon the expression. And guns aren't my favorite subject by a long, err, shot, though.
Shootout duration: Pretty straightforward -- it'd be over in seconds, and even reloading adds little time. Not much to say. Except that the slow motion shot of Kari firing that automatic weapon, and certain undulations resulting from the recoil, was rather captivating.
automatic weapon on stairs: Not surprising this didn't work. Nothing about that horrible movie made any sense anyway. And it stands to reason that weapons would be designed not to go off if bumped.
Nailgun: Interesting how accurate it was at range, given it's designed to work right up close, but how little penetration it had. I wonder, though, if they shouldn't have used a ballistics-gel target instead of wood.
Quick draw reaction time: This is so much like the kendo myth from last week. And they're making the same misinterpretation, assuming it means that reacting is faster than initiating. In this case, the movie situation where the bad guy draws first and the good guy gets the shot first, the idea isn't that reaction time is always faster; the idea is that the good guy is more skilled, has faster reflexes, and is a bigger badass than the villain. It's always cooler to win when you're at a disadvantage.
The other thing that bugs me is that I don't think the result that Kari had faster reaction time was valid, because she fired too early, while the gun was still pointing down at an angle. So that doesn't really count.
It's interesting to see K, G, & T do one part of a myth and Adam & Jamie do the other part (the face-to-face paintball shootout), but I'm unsure of what that does to the results, since it's not the same people doing the different parts of the test, so how do we know the difference wasn't between the people rather than the situations? Basic science: you change only the variable you're testing and keep everything else the same.
Weird bullets: It's surprising how inaccurate silver bullets are. That really dismantles the whole Lone Ranger scenario, where he shoots so accurately that he can always shoot guns out of people's hands without killing them. As for the engraving, I'm not sure if I'm surprised that it didn't throw off the accuracy, but I do find it surprising that the whole "bullet with your name on it" thing has been literally depicted in the movies. I always took it for a metaphor.
Shooting a moving target: Again, no real surprises here -- running from a hail of bullets isn't as effective as the movies say. At least, all else being equal. There's a factor that doesn't really come into play in a paintball test, and that's the psychological element. I've read that soldiers in combat often shoot to miss, that they can't really bring themselves to shoot to kill and either deliberately or unconsciously avert their aim. Who's to say henchmen wouldn't have similar reluctance? (Although that wouldn't explain how the hero is able to mow them down easily. It would require the hero to be more of a sociopath than the villains.)
I think that's all of it, aside from the recaps of stuff from old episodes. (I don't think that "shooting at zombies" clip they showed ever made it into a US episode.)