Ballistic chard showed the the 30-06 dropped only 10 inches at 500 yards more than the 300. They were pretty much equal to the 400 yd point in velocity, and drop in trajectory. Big difference was at 500. Was really nice to find a good ballistics chart
Don't believe everything you read, the 300 is significantly better all the way out, trajectory is only one small part of actually hitting something beyond 200 mtrs. Time of flight is another big factor which is what allows the wind and other things to affect your bullets flight, then there is mirage, optical illusions, animal movement, and a great many other things that can and will go wrong. The 300 WM is a good 300 fps better than an 06 with any bullet weight, so don't believe all the books and charts. If you really want some great shooting experience, join a club that shoots high power and rimfire silhouette. You will learn volumes about long range shooting out to 500 mtrs. ACTUAL trajectories, mirage, energy on target, time of flight, temp variances and how to dope the wind.
One rule that I have learned, hunting all over the world in a hundred different climates and altitudes is that velocity is your friend...........there is no downside to more velocity, except perhaps meat destruction, which is usually of little concern to me as I can't bring the meat home anyway. With the bullet construction today there is no reason not to go faster, and faster, and faster when possible. Oh ya, recoil does go up as well but you can condition yourself to accept any level of recoil up to 50-60 ft/lbs quite easily. I may be alone in my thinking but I will readily give up 1/2 moa of accuracy to gain 200 fps, or even 100 fps. For hunting I don't need my sporter weight rifles to shoot 1/2 moa, 1 moa is more than adequate for taking game out to 750 mtrs easily. If you really think about it 1 moa means under perfect conditions with the range known and your rifle sighted correctly, you should theoretically be able to hit a moose in the heart, first shot at 750 mtrs. How could anyone possibly need greater accuracy than that, for hunting.
Having said all that, if you are going to be the average local hunting kind of guy that will likely never shoot more than a 100-200 rounds a year and likely won't be shooting at game beyond 250-300 mtrs, any CF cartridge from the 25-06 to the 30-06 will fill your needs more than adequately. If you are recoil sensitive then drop back to a 270 or 25-06 or 6.5X55 with good bullets and the game will never know the difference. Sight your rifle in to hit dead centre at 200 mtrs and you can hold the same place out to nearly 300 mtrs.......which is a long shot on game, regardless of what you may hear or read!!!! The difficulty level of cleanly hitting game beyond 300 mtrs goes up exponentially, not linear, 400 mtrs in the field on game is a very difficult shot unless all the stars are aligned right and the Gods are smiling on you, and you have done your due diligence with practice and know your rifle, cartridge and load intimately.
Having had access to a range with targets out to 635 mtrs (15 mins from my door) for the past 35 years of my life has been the greatest asset to my shooting ability ever. It is the one thing (besides a few friends) that I am truly going to miss about the Yukon. The knowledge gained by having that ability to go anytime and play right out to 600+ mtrs is unmeasurable and I have told the guys in the club there as much. A lot of places are hard pressed to get 200 mtrs, and even then you they may have to travel for an hour or more. Now I'll be lucky if I can get 150 mtrs on my property safely to shoot and the nearest range is an hour away and only has 2 or 300 mtrs. I will miss the Whitehorse Rifle and Pistol Club and the range we built very much I'm afraid !!!
However it is +4 degrees here and -30 in Whitehorse, so.........................