I got a Nerf Hailfire a few months after it was released and when I tried to shoot it it was awesome, for a few seconds. After shooting a few darts the dart pusher would just skip over the top of the darts and not push them any further. The clips were all the way up and the darts were new out of the box so they weren't squished. When it did hit the darts it would only push them half way so they wouldn't shoot. Any ideas on how to fix this? It has been bothering me since I got it because I have never got to use it in a Nerf war.