Is a 168gr SMK enough bullet for antelope @ 300-400 yds out of a 30-06? If not, what would the maximum range be for correct bullet performance/energy? I'm loading for someone, and am looking for a bullet (that I preferably have) that will work from 0 - 300 or 400 yds. The gentleman who I am loading for probably would have nightmares @ 400 yds, but I'd like to prepare for that distance just in case. Thanks.