Definitely use the 300. I drew a once in a lifetime tag last year and hunted december 1-3. We saw a decent amount, but a lot were broken horns, and they would take off if they saw you even a long way off, so getting close was tough. It took me three stalks to harvest a 39' cow on the second afternoon with a 487 yard shot. We stalked it almost 3 miles to get that close. I hit it about an inch behind the shoulder and it took it like nothing happened. Luckily it ran over a ridge a stopped. Went after it and it dropped on the second shot at 322 yards. If you do draw on range I'd recommend an outfitter as its a short timeframe and a lot of land. I used Antler Addiction Outfitters as I hunted with them before and became friends with the owner. I didn't know it, but they have a reputation as one of the best for oryx.