Royce. I'm not doubting your experience and can only state my own. I have to ask, what bullet (S) were you using?
Elk #1, 150 yards running full tilt. Bullet hit just behind the short ribs, exited between the right shoulder and neck. Vedry hard bang flop.
Elk #2, 350 yards, bullet broke neck, bang flop. I held for the chest but bullet hit neck due to scope that that failed. Neck bone totally shattered.
Elk #3, bullet hit a bit too far back. Elk anchored, requited a finisher. Shot at 180 yards.
Rifle a custom on a Mauser action, 1 in 14" 24" twist barrel. Load a stiff charge of Re15, RP brass and the Barnes 225 gr. TSX for all three elk. Accuracy .50" to .75" depending on how well I'm shooting on any particular day.