i think a barnes ttsx bullet with a mv of 3000fps would penetrate as good if not better than a 150gr np. i have shot them clean thru 1/4 inch tempered steel at 100yds- just for kicks. and have put them clean thru both shoulders of a white tail with drt (dead right there)results.a hole thru both lungs is all it takes. good luck hunting and don't under-estimate the 270win.