I think you need to weigh your own ability, willingness to pass up shots, the terrain your most likely to be hunting, the bullets you'd use. 6.5 swede with heavy handloads in lapua brass in a modern rifle, with Barnes 127 ttsxlr, will outperform a '06 with 150 gr. cup & core bullets. How far are you willing to shoot, or not shoot? 168 gr. in the same bullet in a .280AI will out-perform at all distances all others you have listed. I believe .300 Mag is the best elk round ever made, but not everyone is comfortable with that much recoil or the weight of carrying it.
