On the line it can be a crooked cut macroline, get some new macroline and cut it straight should fix that leak, if not check the oring inside the macroline fitting as well. And the leak in the barrel is most defiantly a oring. Heres a Smart Parts Ion "bible" lol Anything you ever need to know about it is right on this page. (http://www.gogowners.com/showthread.php?t=3216This) You might have to register but It shows you all the problems and solutions for that marker. Hope I helped! Good Luck
So I have it all taken apart (I can see why people say get the BOB kit now!!). I have my bolt I want to replace the o ring on it. How do I get the old one off?