You have good reasons for going leadfree, I've been doing Barnes for 30 years. The .277 130 TTSX will kick the stuffing out of any elk (surprised just the Accubond was mentioned for elk) on any sane shot including strong quartering from either end. No experience with the Accubond. Not because I don't think it would do the job but the TTSX out of every one of my rifles shoots accurately and punches way above its weight in terms of terminal performance.
My 270 Win shoots the 110 TTSX, '06 shoots the 130 TTSX and 35 Whelen AI shoots the 200 TTSX. The first two cartridges have taken pronghorn, deer and elk with the listed bullets, the Whelen AI mule deer and elk. Haven't recovered one yet from any species with any three of those rifles, which says more about the ability to take something besides a broadside shot which those rifles have very capably done with those bullets.