Wrong my friend. In Halo 3, 3 body shots followed by a head shot (provided all bullets in the BRs burst hit) would kill. In fact, IIRC, the entire 4th burst wasnt even necessary as I think the 1st bullet of the 4th burst finished the shields off, the 2nd (to the head) would kill and the 3rd bullet was unnecessary. Now its the same with +1 shots necessary added in as the BR is now 5sk. This is all after not having played 3 since Reach came out but I am fairly certain I am correct on this.