I used the 140 grain elite hunter in Africa last spring and it worked flawlessly on Kudu, Nyala, Impala and Warthog. All one shot kills. No issues. Shot the Kudu at just under 400 yards, the Nyala at 187 yards, the impala at 288 yards and the warthog at about 70. It did not drop any of them in their tracks but none went more than ten to fifteen yards from where they were hit. Would not hesitate to shoot deer and antelope with them here in the states either. These were shot with a 6.5 x 284 and the velocity was only 2760 fps as that is the velocity where my rifle shoots the best groups. I have not personally tried the 143 grain ELD-X yet but have a 6.5 Creedmoor that shoots them fantastic, just haven't had a chance to get one on an animal.