Ripp is 100% correct. Here's something most men miss:
Look at the velocity of a 30-06 and a 300 Weatherby at range. (we don't shoot animals at bayonet distance very often)
A 30-06 usually will start a 165 gr bullet at about 2800FPS The 300 will do it at 3200 FPS
At 145 yds the Weather bullet is as fast as the 06 bullet is at the muzzle.
So it's realistic to say a 300 Weatherby is the same as a 30-06 with an additional 145 yds in range.
Does that matter?
It may if you can CONSISTENTLY hit your game in the lungs at past 500 yds, but few hunter really can. Many claim they can, but if you put them to the test in a realistic way you find out different.
Such a test is to put 12 inch disks out at unknown ranges from 450 to about 800 yds on a hillside. Walk with you man and at your choosing tell him to shoot. no more then 2 rounds per target. No targets to be shot at from the same place as the last target. Every target to be fired at from a different place at a different range.

Shot 4 such targets from 4 positions using 8 rounds.
Now go get the targets and see how many are hit well.

A real good rifleman will hit over 50% of his shots Most hunters will land only 1 or sometimes 2 bullets on all those targets. Would a 300 mag help? No!
Will it hurt? No! (unless the extra recoil makes them flinch)

As I said before, the question is always about the shooter far more then it is the rifle.
I do now a few shooters that use black powder Sharps rifles in calibers that throw bullets at no more then 1400 FPS and they can hit over 50% of their shots on this test. But they KNOW THIER RIFLES AND HOW THEY SHOOT.

I have made a lot of long range shots with my 270 over the years, but that rifle is now on it's 3rd barrel. I shot the throats out of the first 2.
THAT'S the reason I got to be good at it. Not because I had some special rifle. Shooting a lot and trying to learn from every shot will do a lot more for you then buying a faster rifle.
Look at the records of USMC snipers in Viet Nam and even today. The 308 (7.62 NATO) with a 173 grain bullet is not exactly fast or flat compared to a 300 mag. But Marines sure made them count. In Viet Nam the average was 1.2 shots per kill on NVA and VC. Compared to 1 kill per 246,000 rounds for the other combatants of the war, 1.2 per kill sounds pretty good even with the "slow pokie" 308.