I really think you should considera 165 grain bullet for long range shooting with an ultramag. The 165 velocities are still 3350 + Fps and the there are bullets out there that can stay intact at close ranges. The BC of some 165s are so much better that their trajectories will pretty much equal out with the 150s at 500 yds. The barnes triple shock with .505 BC would be a greatchoiceif your gun shoots them accurately.