Flat shooting is good. I used a .308 my first year... plenty of punch. It doesn't take a lot to bring an antelope down. I have since bought a Browning A-bolt 25-06 that I use when not archery hunting antelope. It is a very sweet shooting gun for antelope. One important thing that people do not mention is the bullet. 117 grain in the 25-06 is good. I prefer a bullet that "expands" on impact and does damage as opposed to a bullet that goes right on through with little damage being done. Antelope are not tough critters so you do not need some jacketed bullet.
Secondly, I prefer as close as possible. Some people are into this "long range" stuff. The distance that you prefer to shoot will also determine the gun, to some extent. The longest shot that I've taken was 244 yards... the closest was 77 yards.
good luck to all
"it's the HUNT, not the KILL"
2002 & 2012 Realtree Turkey Contest Team Champs!!