I don't think it exists.

If I was forced to choose something else as a perfect deer cartridge second to the 270 Win. I would probably go with the 6mm Rem then the 280 Rem.

I just don't there is anything available that kills deer better than the 270 Win. With 130 grain bullets it shoots nearly as flat as any magnum out there with a +-3 inch range of rise and fall to 300+ yards, ammo is available anywhere that ammo is sold, it is inexpensive, you can choose a rifle or a dozen from every single manufacturer.

It's not sexy or glamorous but it does its job at least as well as any other cartridge out there and far better than most.

I guess it would also depend on where I was hunting. If it were thick woods where a 50 yard shot would be considered long I'd probably pick something like a 30-30 or 35 Rem.