Haven't done a vast amount of eland hunting, but have done enough in three countries to know they're not hard to kill, but a really big one requires plenty of penetration, both on bone and angling shots. The hunting also often involves long tracking, with the shot finally coming at an alarmed eland, heading the other way. I would personally choose a relatively lightweight rifle in any medium-bore cartridge from the .338 Winchester up with monolithic bullets, or near-monolithic bullets like the North Fork. Such bullets penetrate noticeably deeper than wider-expanding lead-cores like the A-Frame and Woodleigh, no matter how much weight the lead-cores retain.
The reason for the lightweight rifle isn't just carrying it on a long track, but the higher likelihood of having it in your hands, and then getting the rifle up and aimed quickly, when the chance comes--which may be brief. If I had the chance to go right now would probably pick my 8-pound 9.3x62 with 286-grain TSX's, or possibly 286 North Forks.
