Given your range parameters, I'd probably choose a tougher bullet, regardless of weight. The weight of the 129 AccuBond Long range isn't a problem, but it's designed for long-range performance--which means beyond 400 yards.
Elk are big animals, and despite the obsession with tiny groups these days, at the ranges you shoot 1.5" 3-shot groups at 100 yards are more than sufficient for hitting them in the right place. I know a lot people recommend "whatever shoots best," but at your ranges bullet construction is more important than either pin-point accuracy or weight. As an example, the 127-grain Barnes LRX would work fine.
Among the many bullets I'd recommend would be 120-130 monometal bullets, or tougher bonded/partitioned bullets from 125-140 grains.
