A friend has used a 6MM Rem on whitetails for many many years and with devastating results. Absolutely any 100 grain bullet seems to do the job with Remington Core lokts being most used.

My less than optimal result were deer that ran a lot farther than when I used the other bullets. Small wound channels and exit wounds plus I had to shoot three of the six deer I took with the 100 grain Nosler partition twice. I think the 6MM's mass is not enough that the front section flying apart doesn't do enough damage. Next year I am going back to my 30-06 (this year is a 270 year) and I am giving the 180 grain Nosler partition a chance to show it's colors. I try to stay away from my 30-06 because every time I use it I start thinking why keep all these different rifles?