RE: 270 and Elk
I would definitely switch bullets. I had used 130 gr. BTSPs, more precisely Sierra Boattails. I killed one elk and several bucks with the bullet. What I discovered over time was that the bullet has a tendency to blow up into shrapnel at close range and high velocity ON DEER. I shot bucks at 35 and 25 yards, hit major bone on each shot, and the bullet blew up. Now, it killed both animals but I wonder how the same shot would have turned out on elk. My only elk kill was 350 yards, so the bullet had shed velocity by then and made for a nice one-shot kill.
Both me and my stepdad have changed over to Scirocco bonded bullets, and have now killed multiple elk with it. I got a clean pass-through on a huge cow elk last year at 90 yards.
That summarizes the data I can offer. I would lean toward the 150 gr. Nosler Partitions, in fact I am going to try the Federal Premium version this year and if they shoot well out of my rifle I may switch.