Personally even though I love 7mm diameter bullets regardless of what cartridge it's fired from, the 300 win mag has served me VERY well on elk so out of those 3, I'd grab the 300 without hesitation. I'd rather have a 338 mag but the 300 with a 180 gr accubond drops mature bull elk just fine. If mostly for deer I'd grab the 28 Nosler, and if mostly for elk, and within 300-350 yards I'd grab the 35 Whelen or 9.3x74.