curious to know if
@chamois has any first-hand experience on oryx, and what his recommendation would be.
I have shot a number of Oryx in Namibia with several cartridges going from a 5,6x57 loaded with 62gr TSX to a 300 Wby Mag loaded with 160gr GS Custom HV bullets and the former 180gr Barnes MRX.
The ones with which I have killed the most have been a 6,5x65R with which I made a side by side comparison between the 140gr VLD and a 93gr LM KJG bullet. The latter is a copper monolithic bullet whose front part fragments @ la Hammer or Cutting Edge styles; a 6XC loaded with 105gr VLDs and a 7x57R with 150gr Partitions. In that order. In all these cull hunts my hunting buddy always used a 270WCF loaded with 140gr NBTs so I also have a good feel about their performance.
Oryx have a very particular anatomy with the heart placed lower and further to the front that you would think. Also, the spinal apophysis of the vertebrae in the neck shoulder area are quite long, meaning that, roughly, that a shot in that upper third of the Oryx silhouette will not touch the spine, even less get into the rib cage.
In my opinion, if you place your first shot well you have a dead Oryx but, if your first shot is not well placed you will not believe the amount of punishment your wounded Oryx will take before folding up. If he runs out of sight after a first lousy shot my bet is that you will never find it.
I attach a photo of my favourite shot on Oryx, the one I consider more lethal (excluding spine or headshots) which is two-three inches above the edge of their black stocking. This one maybe is a tad low but you get the idea. I will try to attach a short 12 seconds video of an Oryx killed with that very same shot from the 93gr KJG and the 6,5x65R.
Sorry for the long text.

PS: I have not been able to load the video. It does not seem to be possible, but let me know if you can and we will find the way to send it to you.