RE: 270 trajectory
Hey Stubble - my thoughts exactly.
Dead on - Your logic on bullet trajectory is dead wrong.
If you were to plot your 2 bullets you would probably see that the lighter bullet crosses the line of sight at a farther distance from the bore than the heavier bullet and is continuing to climb at 100 yds.
(ie. with a 200 yd zero from the Hornady manual, a 100 gr .277" traveling at 3600 fps will be .40" high at 100 yds whereas a 130 gr bullet at 2900 fps will be about 1.14" high.) This is considering a 1.5" high line of sight above the bore.