I carried a .243 as well on my first hunt, and have used every one of those factory 100 gr. loadings from Remington, Federal, and Winchester to take deer and antelope. I probably used more Remingtons and Federals, simply because that's what the stores I could afford carried.

My recommendation is to take a box of each to the range and see which shoots the best in her rifle (by "best", I mean which one shoots the tightest groups).

I haven't had a single problem with any of those bullets as long as I did my part getting it where it needed to go.