Video proof of the problem above.
A couple of users, including myself, have run into some issues with the old 18 dart Stampede mags, (Have yet to check with any other magazine). Unmodded, the only way constant firing you’ll get out of the blaster is to use the half clear 18 dart mags they sell at stores with Elite Darts. This is a big problem and can cause all sorts of reliability problems in games.
When you load a mag, the dart puts pressure on the orange lever above, and unblocks the plunger so it can hit the dart through the flywheels. A simple, but temporary fix, is to use duct tape to put pressure on the level all the time.
However, my friend has opened the blaster and found a very simple way to fix this issue. He reports that it’s working great with zero jams after doing this. So be sure to check it out and tell him I sent you!