man pages in c-mode

[Hadron]

I thought this might turn my man page display into c-mode. It
doesnt. What must I do?

(defun jump-man-page ()
  (interactive)
  (manual-entry (current-word))
  (c-mode)
  )

Note that I call manual-entry in "aggressive" mode meaning that
manual-entry puts the man page into another buffer and sets focus
there. I can then manually set c-mode with no problem using

M-x c-mode

But how to do it from my function which is bound to a function key?