Let me start by saying this isn't a "which one is better comparison." Just sharing some events from most recent elk hunt. Also, we weren't planning on taking long shots this time around hence why the 6.5 was brought along, so I'm aware that the 6.5 is a bit on the light side for long shots at elk. Now for what happened. It was the last day of our hunt so we were getting desperate, having chased (unsuccessfully) 7-8 elk we spotted through thick timber the days prior. We decided to head to some more open areas the next morning. As we were coming around the ridge, boom right there across the valley are 3-4 cow elk standing broad side not noticing us. We get set up and my buddy calls the ranges. It was overcast and rainy and his rangefinder kept spitting out anywhere from 585-620. We decided since it was the last day now was our chance. I was running the 6.5 creedmoor with a 143 Eld-x and my other buddy was running a 7mm rem mag with a 150 gameking. I take my first shot, hit right behind front shoulder. It takes it like a champ and and starts walking down towards the timber line where we would lose her. At this point, my buddy takes his shot where she then walks 10-20 yards and drops. I pull back up at the last cow elk still standing broad side. Boom, I hit a bit low since I maintained my holdover for my first shot which was slightly closer. It hits what appears to be somewhere bottom of the chest towards front shoulder, and I can see a huge blood mist from the impact even at that range. Sweet, that's a gonner for sure (I thought). We spend the next hour or two getting over there since it was across a canyon. We find that first one dead on the ground and start quartering it out. I will skip that PITA chain of events hiking all that meat to the nearest trail. We see an obvious blood trail for the second one. I'm seeing bright red bubbly blood with patches on the ground ranging in size anywhere from pennies to paper plates. Great, this shouldn't have gone far. Long story short, we spend the remainder of the day tracking that elk across the entire mountain and ended up losing the trail in really thick brush/timber. We searched as hard as we could but no body was to be found. I couldn't believe it. I guess all those stories of elk being bullet proof really were true after all. Anyways, we got meat so still successful. But after seeing the the meat from the first elk and seeing the 7mm obviously did the most damage, I was curious. I did some calculations at at that range with those bullets, they are almost exactly the same velocity and energy! On paper they should have been the same but in the real world that 7mm dropped it where my 6.5 was faltering at that range. Anyways, share your thoughts and experiences.