Yeah I had to put locktight on the little rod part but that was it. I don't know why you had to locktight the thread that adjusts the fps. Wouldn't that mean you can no longer adjust the fps because locktight is keeping it there? The metal part I was refering to was the same one that broke on this guy.
http://www.airsoftcanada.com/showthread.php?t=102993
im not sure if your bbs aren't coming out because they are hitting something in the inside of the extended barrel. Or if the tightbore barrel is too tight maybe? Or there is not enough compression pushing on the bb. It's hard to tell. Since you have a stock hop up and a stinger hop up. And a stock barrel and a "precision" barrel. You should install the stock barrel with the stinger hop up, or the precision barrel with the stock hop up. That might narrow down where the problem is.