I would definitely plan on using a rifle on such a short term hunt. Watch the weather...if the forecast is cold and windy you better not pass up many oryx or you may not get one! They are extremely tough to find once the wind starts blowing because they hide out in the tall (6 to 12') brush. Their heart-lungs are between their front legs so if you shoot behind the shoulder you have just gut shot them. Use a 30 06' or larger, shoot through the front legs to anchor them! They are extremely tough animals and can take a pounding from lead so make sure you have a good shot!
They now conduct searches of your truck and vehicle. Adhere by the missile range regs or you may not make it through the gate or get escorted off the range without an oryx! Bring a couple spare tires because I've had at least 1 flat tire on each hunt I've been on. The oryx on and off the bases have been hammered by increased tags the past 5 years so it is a lot tougher hunt than it was a few years ago and from what I've seen there are a lot higher proportion of broken horned oryx running around.