This ain't my first rodeo, Balog. I got soured on the eargesplitten loudenboomers back in my long-range competition days. Those rifles were heavier than hunting/sporter variants, yet still punished the shooter over the course of a match.
Shooting them from the prone bipod was absolutely no fun at all. The barrel life at factory and top-end handload data is not so great, either.
The higher working pressures and the bead-blasting effect of all that extra powder going through the chamber throat and burning further down the barrel raise hell with things over time.
I actually competed against a guy at a 500 meter sniper match who had his 7mm STW rig wired with a barrel-mounted thermocouple and digital display, so he could keep the chamber end cool and lengthen his barrel's life.
Overbore rounds certainly get the job done, but it's no free lunch. The quest for more fps is one of diminishing returns once you get past a certain point.
The .30-378 Weatherby Magnum is one hell of a round. It also has a barrel life measured in the hundreds of rounds. You'd better get your favorite handload dialed in within 20-40 rounds, because the clock's ticking before the throat is washed out.
That's why I settled on my own 6.5-06 for 1000 yard work. The bullets stay supersonic well past 1000 yards, yet the recoil is minimized and I'm not overbore like the .264 Win Mag and others.
Hence my saying you should explore what that .270 is capable of. At .277" bore, it's darned close to a .264, and IIRC Walt Berger even started making VLDs for that caliber.
Although, the long-range rifle that sees the most trigger time from my gun safes is my own 1874 Sharps Business Rifle.
535gr Postell cast by yours truly, beeswax and lard lube, a card wad, then 70gr of Goex Cartridge grade Holy Black. 32" of burn time, Creedmoor sights with spirit level. My own kind of Magnum!