Ooh ooh my turn. 6.5 PRC, 7-08, 6.5 CM. We can salivate over long range performance, but as OP said, 400yards max. When you cut it off there, you have the following (all with Hornady precision hunter eld-x for uniformity. 100y zero and 20mph crosswind):
6.5 PRC: 2477 FPS, 1949 ft-lbs, 23.1" drop, 13.4" drift
6.5 CM: 2244 FPS, 1598 ft-lbs, 28.9" drop, 15.3" drift
7-08: 2268 FPS, 1713 ft-lbs, 27.6" drop, 16.2" drift
They all meet velocity minimums and energy "minimums". The PRC is the straightest shooting. Let me add the 25-06 (would be my choice if I were to buy an antelope specific rifle).
25-06: 2478 FPS, 1500 ft-lbs, 21.3" drop, 17.1" drift
Bottom line, they all do the job. 6.5 cm and 25-05 recoil the least. 6.5 prc the most (although still not hard). The biggest drawback to me on the prc is barrel life. 900-1200 rounds is what's reported for barrel life. If you're going to shoot a lot in preparation, it doesn't make a whole lot of sense to have to rebarrel every 2-3 years. All the other choices beat the PRC by thousands of rounds in barrel life.
I would take 25-06 and then 6.5 cm for antelope within 400y. Just my $.02
Now all that being said - I only own one of these, and it's the 6.5 PRC lol. I absolutely love it, and will be taking it for antelope this fall. I bought it as more of a western deer gun, and planned to buy a 25-06 this spring to use for antelope this fall, but I don't feel like spending that money right now so the PRC is coming with me. I certainly will be buying a 25-06 in the near future though.