well the SAW uses the 5.56 NATO round just like the M16, and has a longer barrel than the M4 (which you can fire on fully automatic) so it has a little more range on a point target. ive never fired an M60 because we dont have them anymore, but i think it used a 7.62 NATO round which makes it more comparable to the M240, which is the new 7.62 firing machine gun. eh who cares, its a freakin machine gun......awesome.