i had exactly the same idea about cameras before, so i tried my nokia 6230, taped just in front of the foregrip.
not a good idea, one hit to the phone shattered the case wrecked the battery compartment and managed to crack the screen on the other side!!! and that was through 10 mm of protective foam!
can you post a link to the cam you baught so i can take a look please?
i was thinking about a wireless bullet cam, but how do you record the image? a camcorder in your battle pack? or an mp4 recorder in your pocket?