I am putting together a gun for my wife to hunt deer. I am using my TC Contender and making it into a carbine... Anyway I thought you guys might have some ideas on which cartridge would be the best for white tails...

Here are my choices.

7-30 waters
6mm TCU
6.5mm TCU
7mm TCU

Any opinions/comments/experience with these rounds? I am probably leaning towards the 7-30 waters, just because I am a little familiar with it. Thanks!