ChIck3n

Any reason you took the on/off safety switch out? The pressure locks I understand (and have removed all but one clip lock in mine), but with the stampede sometimes developing runaway issues I would be hesitant to take the switch out. You would need to remove the batteries to cut the power in this case, which would also be bad mid game! If reliability of the switch is your concern, you could always replace it with a better switch.

I may have diagnosed it! Followed my initial instinct and gutted the thing to he gearbox. The gears themselves seemed fine, but somehow the gearbox itself had shifted. It was bent open about 5mm around the seam, so I pulled it apart, reseated everything, and it closed up nicely. Fired great for a few shots, but now the problem is back. Gotta run now, but looks like a gear/gearbox problem (I'll see later if it opened back up). Guess I just need to find another stampede and try swapping the gearboxes.

Well, I checked and replaced the catch spring and it still happens. It is firing fine, just not opening the dart stop up in time. I can shove the dart in and hold the dart stop open, and it fires the dart just fine.

Your runaway problem may be fixed by following SGNerf's guide Here
As for the dart tooth problem, I have also wondered how to fix that as it's happened to me a few times.

Ya, I went over that guide and even tried replacing the springs with stronger ones from pens. No luck. Ran it by SGnerf on his forums (he's the one who told me about not tightening the screws too much), but figured I'd try here as well.

Here's a video of the problem if that helps anyone (Ignore the mag stuck halfway in, it's just to hold the electric lock down (and I realize now is why the trigger wasn't working) because I had to record with my ipad in the other hand.):

Ah, thanks for all the help. I may look into that toggle switch if I can find a place to stick it, as the goal I have in mind is to be able to operate it quickly and easily with one hand while changing mags with the other.

Though if there is anyone out there who knows more about the electronics aspect I would love to hear from you. If there is no safety risk of occasionally firing both at once I'll just stick with the second thumb trigger. Not really overly concerned about a little extra discharge rate, as I can charge it between HvZ missions. If I go through enough darts to discharge the batteries I still have a backup set, and if I go through them the zombies have earned their kill. Dead batteries = OK, exploding batteries = not OK! I've done wiring and stuff before, but am not sure what exactly an "unprotected" battery means and what is no longer being protected.

And I'll be sure to post pics and maybe a writeup when I'm done.