So, the main issue that I'm having here is that when the plunger tube assembly moves forward, it gets stopped about halfway by the gears in the gearbox. I tested many different "rotations" of the white gear inside the gearbox by manually priming the blaster but it always gets stuck about halfway. When I lift the plunger tube assembly up a little bit from the shell (so that there no longer is any gear contact), the barrel/ breech assembly is able to reach the dart tooth area just fine. From comparing my internals to pictures on SG Nerf's website, they seem more or less the same. (3rd picture here: http://modworks.blogspot.com/2010/07/nerf-stampede-internals-guide.html
-When firing normally (ie with batteries, etc. instead of manually priming) it makes a really scary grinding noise similar to if you sampled the firing sound of one shot from the stock Stampede and continuously looped it with no pause between shots
-Also when firing normally, the dart does not leave the clip and the breech/barrel does not move forward either
-I originally popped a Home Depot Handyman spring I borrowed from my Nite Finder which caused the dart to move a little bit. I also somehow placed the plunger tube endcap (the circular piece with the square hole in the center and the white ring around it that screws onto the back of the plunger tube with 2 silver screws) upside down but I quickly fixed it after the 1st test fire
-In order to reinforce for the Home Depot spring I was planning on using, I added a foam pad (from a BBB arrow), filled the plunger rod with hot glue (I used a X-acto knife to clean it up so it doesn't catch on stuff), and I have a 3x4.2 volts (12.6 volts) Li-Po battery setup. Right now, I got rid of the Home Depot spring and have everything else the same (but I fixed the end cap of the plunger rod of course).
-When removing the ARs, I did not have a drill bit long enough so I had to pipe cutter the bolt apart at the seam (between the orange and grey plastic tube sections before the plunger tube) but I have since sealed it back and cleaned it up so it won't catch on the plastic ring guide that holds the black return spring back.
-I have tried moving the gear inside the gear box around with a flat head screw driver, but no matter what orientation it starts off with, it doesn't seem to work when manually priming. If I lay the Stampede down and look at it from the top (where the jam door is) I can see a white gear with two halves. The bottom half is all teeth while the top half is about half teeth and half no teeth. If you imagine taking the circumference of it out and laying it flat like this: _______________^^^^^^^^^^^^^^ , should I rotate the gear so that the toothy part sticks out when un-primed or the flat part?
*If pictures would help, I'd be more than happy to post them. The reason I didn't yet is because after comparing my internals to SG Nerf's internals guide, I can't discern any major differences other than the parts on the plunger where I had to cut to get the ARs out.
Thanks for any advice/help/suggestions!