I have seen several write ups on forums in the last two weeks complaining of 6.5 creed 143gr ELDx bullets not performing well on closer (100 yds or less) shots on deer. Some saying the exit is the same size as entrance, no expansion, little to no blood trails. If that were the case then they certainly wouldn't expand at longer ranges. Further examination has most believing that the bullet is coming apart and the cup is exiting leaving a small exit. That means this bullet is fairly fragile. The 6.5cr isn't any kind of a speed burner with the 140+ projectiles, and folks using them at longer ranges seem satisfied with the performance.
Interlocks, I have used them since Academy came to my area and had the Hornady custom ammo on the shelf which used the interlock bullet. I was shooting 7mm Rem mag and liked the 139 gr. offering. Began handloading and used it too. Pushing it 3100 fps or so I have never had a deer be more than a very short distance from where he was standing. Never saw any reason to look at heavier bullets because the 139's worked well, and I liked the speed. Started shooting a .300 win mag, using 150 gr interlocks, liked the speed and accuracy, but I was less than satisfied with the performance on deer. Every single one I shot ran, a couple over 100 yds. Our country wasn't too thick, so I never lost one, but I am lazy and don't want to worry about losing one. Went back to my 7mag and later started using high shoulder shots, and the 139 gr performed well. Never had a failure to exit, so I don't know if they came out in pieces or mostly intact.
As a matter of fact, I have only had 2 instances of a projectile failing to exit a deer, and one was a 30-06 federal 150 gr (cup and core, not sure which one,it was in the mid 80's. Fed factory load) that I shot as the buck was facing me 25 feet away. Shot him right where I envisioned the heart to be, and he turned hard and ran 15 feet and directly into a tree and fell dead. The bullet was under the skin on the back side of his right rear leg. Looked like a perfect mushroom you would use for advertising your bullets.
The other instance was buckshot at 10 feet or so, and 3 pellets were still in the deer, the remaining 6 (2 3/4" 00) either exited on the front quarter left side, or left marks where they skinned hair off. One such mark was 2' long, we all wondered how it stayed on the skin so long.
I now shoot 25-06 due to back surgeries and other health issues. I have found good loads for my Tikka T3lite, and weatherby mkv ultralight using nosler 115gr ballistic tips, and 115 gr partitions at 3100 fps. I just bought a box of 117 gr interlock btsp's and have not worked up loads for them yet. I am a little concerned about the performance of the BT's, and their toughness, so I most likely will be hunting with the partitions, because I know they will stay together. Since the 117 gr interlock will be driven as fast as I used to shoot the 7mag, I feel like they will work well on deer.
I sold the 7 mg and bought a ruger predator in 6.5 cr, because I felt like I needed to get on that bandwagon, hence my first paragraph about the eldx performance. If I deer hunt with this rifle I think I will use partitions in the 125gr for more speed. I got a 100 bullet box of eldm's140 gr, as I may want to try some longer range shooting. I have never practiced over 200 yds, although killed a couple of deer near 300. I know that the predator isn't the best rifle to do LR with, but maybe I can get my feet wet.