I loaded the 143gr ELD-X in my 264 win mag I had built for long range shooting. It is shooting really well with them at a muzzle velocity of 3240fps.
I shot one of the biggest bodied bucks I've ever killed, maybe ever seen with that rifle this season. He was a 6 or 7yr old buck that had been around a while, never developed a great rack. This year he became the dominant buck of the area and was whipping all the young bucks with good genetics so I decided to target him. I shot him at 150yds as he started to run off and hit him straight through the front shoulder. He dropped instantly. When I quartered him out I found that the bullet had fragmented on the shoulder and I never recovered a piece big enough to weigh. Impact velocity was still around 3000fps so it was asking a lot of a non-bonded or monolithic bullet to hold up. It did the job, just not quite like I'd have preferred. If I'd have hit the lungs results may have been better.
During antlerless season I got to try it again. I shot a doe downhill and facing me at 321yds. This time the bullet performed more as expected. The bullet entered high in the front of her chest, exited her belly at the back of the lungs, and broke a back leg on it's way past. She also dropped instantly. Impact velocity here should have been about 2750fps.
Just an FYI for those looking at this bullet. They shoot so good I want to stick with them and plan to use them again next year to see how they perform, get some more animals with them. I think in a smaller case 6.5 or at longer range they will be darn good. From a big 6.5 up close they may be a bit soft. I won't use this rifle on anything bigger than deer, that's what the 300WM is for with 180gr Accubonds. I like a bigger tougher bullet for large animals.