I truly love testing bullets since I have access to a very large "lab"-deer permits, bears, groundhogs.
On these hot days I watch a few outdoor shows. Most don't say a thing about bullet performance or show damage or exits.
Recently, The Best of the West and GunWerks have gotten on the ELD-X bandwagon. They're shooting big stuff-elk, mule deer, gemsbok, waterbuck, kudu, moose with them.
Two years ago I took my first deer with my 6.5/.284 Encore and the ELD-X at 581 yards. The damage was surprising and puzzling
According to this months NRA American Hunter (and Hornady) the bullet retains 60% of it's weight. Hmm. A rib was hit, but really. The exit was 4". The internal damage was massive for a handgun at that range.
I killed a few more deer with it the last 2 years. All were broadside lung shots. Exits were smallish, so I guess it retaind weight and didn't expand a lot.
This year I took an unaware deer at 149 yds. It was quartering away. I hit the mid rib cage on the right. She ran 40 yds. I turned her over to see the exit. There wasn't any. I felt a small lump on the left shoulder. I cut it out. Was I ever surprised
That's the bullet on the left and original on the right. It weighed 35 gr. (24% weight retention). And guys are shooting very large game with this bullet.
I did further testing with the .25 ca. ELD-X. I took 3 more deer from 170 to 279 yds. All ran a good ways. All damage was around 3". Exits were 2" on double lung shots.
Based on all this, I'm not sure ELD-Xs are the way to go in small caliber or even .264. Sure, I've taken deer with them. Many run. When I go on an important hunt I want near perfect performance from me , my gun, and the bullet. The only bullet I've found close to this is the Nosler AB. It's about as near perfect as I can hope for based on around 500 deer kills, moose, red stag, and around 15 African animals.