The only measure of terminal performance that matters is wound channel creation, and the resultant effect that has on the animal. Weight retention and separation are marketing ploys. It means absolutely nothing unless the bullet is for braining dangerous game or piercing armor. Wound channel creation is the only meaningful metric.
The 140 ELD M I've been hunting with separates about half the time (usually at the end of the wound channel, after hitting heavy bone). The wounds channels they create are incredible at all velocities. They make bonded bullets look pretty bad in terms of terminal performance and speed of demise.
I'd put the 73 ELD M out of a 223 up against most bullets and calibers on deer out to 600 yards. They probably "retain" 20%-40% of their mass, but kill like lightning. The wound channels look very similar to mid size calibers with typical bullets that say "hunting" on the label.
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