To a certain extent it’s just part of deer hunting. There is no cartridge-bullet combination that will always drop deer in their tracks, at least with a chest shot. The only way to drop deer where they stand is to hit the central nervous system, either the brain or spinal cord. These are tricky shots, though, and should normally be avoided. A chest shot normally kills a deer within seconds, but as you’ve seen they can run 50 yards or more in a few seconds. The “problem” you’re having is more a function of bullet design rather than energy. The Trophy Bonded bullet is designed for deep penetration and hence is an excellent bullet for really big game like elk. Since the deer all died fairly quickly, it’s expanding, but not as much as a bullet designed for lighter game like deer. (You can tell if a bullet has expanded, even if it went all the way through a deer, by the damage to the innards.) If you switched to a load with wider-expanding bullets, you’d probably drop deer more quickly–though again, no cartridge will drop deer in their tracks every time unless the spine or brain is hit. I’ve shot deer with the .338 Winchester Magnum, using a rapidly expanding bullet, and some still ran a ways before falling. The one advantage of the load you’re using is that it almost always leaves a very good blood trail, which is not always the case with a fast-expanding bullet that may not penetrate all the way through a deer. An obvious blood trail makes recovery easy. You might switch ammo to a load with bullets designed to expand quickly on deer. Federal’s Classic load with 150-grain bullets is very good, as is Remington’s 150-grain Core-Lokt or Winchester’s 150-grain Power-Point. One of my favorite deer bullets is Hornady’s Interlock: The front of the bullet expands quickly and widely, but the rear of the jacket has a reinforcing ring which tends to hold it together. These usually completely penetrate deer but also drop them quicker than Trophy Bonded bullets. Hornady makes excellent factory ammo using the 150-grain Interlock.