For the opportunity at elk, the 150 gr would be a better choice than the 130 gr bullets. The 150 gr will provide a higher BC and SD which will produce better velocity and energy retention at longer distances, plus give more reliable penetration.
I liked the 140 gr bullets in my 270s (Win, WSM and Wby), as they gave a nice balance with velocity and energy for reliable penetration...but as always, bullet placement is the biggest determining factor. My favourite is the Nosler AccuBond. Great expansion and weight retention on recovered bullets from medium and large game (deer, mtn goat, caribou, moose, and elk).
As suggested above, good bullets make a difference.
I have just picked up some of the Federal 136gr Terminal Ascent ammo to try in my new to me LH Steyr 270 Win. Hopefully it likes this ammo!
I used the Terminal Ascent ammo in my 6.5 CM on red stag @ 296 yards (450 lb live weight), fallow deer @ 267 yards, and my wife used it on her Arapawa rams @ 120 and 122 yards with good results; all one shot kills. All bullets penetrated, so unable to recover a bullet to examine for expansion and weight retention.