What i would do is,

1. Create a "Camera and Aim" not a "Camera".
2. Hit Space so you get 4 point perspective view(4 screens)
3. Go into top view, and while selecting the camera go to Panels and then click on "Look Threw Selected". This Should make the Top View change into your camera view.

As for the camera aim(circle cross hair) place that onto your bullet as this will make the camera looking directly at the bullet ...

Also you must also select your camera and hit s to key frame the camera's movement, if you get what i mean.

Hope you get all that,

Marlon