Final Battle Jazz: what the heck do I do with his gun?

so, the instructions don't really give me a satisfactory explanation of how to attach the gun, Missile 'out' (not in "rifle mode,") to the robot form of Jazz, and I've tried doing it that way just turned around, but then there's still that weird little hangy-clip with the prong that doesn't seem to go anywhere or do anything in any form.... I'm at a complete and total loss.
otherwise, the figure is great.. i guess. it has the same problems that "never been in a fight or scratched the paint" Jazz has: head doesn't automorph all the way, spindly, worthless little hands, and just generally looking sort of extra-stumpy (i think the color scheme may be contributing to that, because I just don't feel the G1 repaint jazz looks quite as "stumpy" for some reason.) I will say, the gun *does* look awesome, but I can't figure out what I'm supposed to do with it. help?
otherwise, the figure is great.. i guess. it has the same problems that "never been in a fight or scratched the paint" Jazz has: head doesn't automorph all the way, spindly, worthless little hands, and just generally looking sort of extra-stumpy (i think the color scheme may be contributing to that, because I just don't feel the G1 repaint jazz looks quite as "stumpy" for some reason.) I will say, the gun *does* look awesome, but I can't figure out what I'm supposed to do with it. help?