I'm surprised the .270 Winchester hasn't got a mention.
I would have thought it would be perfect for Whitetail deer.
Here in the south east of Australia we have Sambar deer that would average around 600 pounds. We stalk them on foot so most shooting is done off hand, no rest. Because of the dense forest, a long shot would be 300 yds.
Over the years I’ve used a .303 Brit, 270 win, 340 Weatherby, 300 win Mag, 30-06, .308 Win., 7mm Rem Mag and .375 H&H. My current rifle is a Ruger 77 Hawkeye in .338 Win Mag.

The .270 I bought in 1979 and apart from the new .338 and an old .303 backup it is the only large CF rifle I’ve kept and used continuously for all that time. With 130grn soft point boat tails it is adequate for Sambar to 300yds and beyond. It also makes a fine varmint rifle especially on those days when the high speed.17 -.22’s are blowing away in the wind. Like a 30-06 you can shoot it all day, even off a bench, without getting a head ache or a sore shoulder.

The Weatherby and H&H are too hard to buy factory ammo for, especially if you are hunting in New Zeeland or New Caledonia, and airlines get real nervous about shipping ammo with guns these days.
The 7mm and 300 magnums I find have a lot of muzzle blast, in practical dense bush hunting rifle length barrels of 22 to 24”. In a stalking weight rifle the larger magnums have too much recoil for constant shooting. Maybe not, if you’re built like Arnold Schwarzenegger, but I’m not.

The .308 Win lacks a bit of power at longer ranges. The 30-06 is about perfect, but like the .308 is restricted in some places due to it military origin and it is not as versatile for varmints as the .270.

If I was restricted to one high powered rifle (a definite possibility in Australia) the .270 Win will do it all for me.