The 30-06 is perfect for antelope! Sure you could use a smaller cartridge, but it won't work any better. I'm surprised some are recommending 125 grain bullets though. In 30 caliber, a 125 grain bullet is going to have a really low ballistic coefficient, which means that although it may start out a little faster, it will also slow down much faster. Which also means it won't drop any less than a heavier bullet at longer ranges, and it will also drift in the wind much more than a heavier bullet. Wind drift would be one of my biggest concerns in choosing a bullet for hunting antelope, as the wind blows most of the time in antelope country. The little 125 grain bullet also will ruin just as much meat, if not more, than a heavier bullet, depending on shot placement, of course. It is not the weight of the bullet that determines how much meat will be damaged...it is the construction of the bullet, the velocity at which it strikes the animal, and again, shot placement. I'm not saying a 125 won't work, because obviously it has worked for some people, but just that it is far from the best choice. A 165 or 168 would be the best choice in the 30-06, in my opinion. Even a 180 grain boattail bullet would work very well. The only advantage by going to a lighter bullet would be less recoil, so if that is what your concerned with, go with a 150. A 125 is just too light to be a practical choice in 30 caliber, especially when you're talking about long shots in windy conditions.