I would use the 270 he has if I were him. I have a old Beretta shotgun that was my grandfathers. This shotgun is in like new condition with a market value of $20,000 to $25,000. I use two or three times every year blue grouse hunting. Just because my grandfather would want me to. After I shoot two limits of blue grouse with it for the year, it goes back into the gunsafe.
My point is his grandfather would be proud to know his grandson is hunting with his old 270. If your friend is like me he would never consider selling this rifle. So the market value of the gun means nothing. The memories are priceless.
Have him try the corelokt ultra bullet. He should also look at other premium bullets. Nosler Partition, Nosler Accubond, TBBC, Swift A-Frames, Barnes-X, Winchester Failsafe.
Just tell him bullets are like broadheads. Some bullets/broadheads work great on deer but just are not good enough to trust 100% of the time on elk.