Thanks for the input guys. I have a buddy coming into town tonight to hunt the weekend. Not my antelope tag. My buddy probably won't have to shoot far unless he has to use my big 338 but I'm guessing I will get him close to one. We will probably look for a bigger one on Saturday. The only reason I think he might be about thirteen on his strong side is because he has fairly high prongs and tips back, down, and inward from the prongs. These ones are hard for me to judge.
Here is a similarly shaped one I took a couple years ago in Nevada. He was right at 14.5" and was taken at a little under 500 yards with my STW.