65BR,
Don't bother trying to convince me ... I'm planning to build one at some stage. You can load for it with 7mm-08 dies with the expander plug removed by the way. In Victoria, Australia ... deer hunting for Red and Sambar deer requires a 277" minimum, 130gr minimum and 2" case or longer. Thus the legalities assist it, though the steep/heavy terrain tends not to.

Here's why it wont be done ... your domestic manufacturers are now inclined to release ammunition with 'premium' on it ... ammunition cost will kill it when it comes to the average shooter/hunter. If you can market it with a dirt cheap load, it will take off amongst non-reloader types. A positive is that a regular 130gr cup/core designed for the 270Win will most likely do exceptionally well anyway in this cartridge. Keep price of ammunition down, it will get bought. I'd be inclined to have its ammunition production outsourced entirely to say PPU who make both a cup/core 130gr 277" plus 308 sized bras in 243Win, 7mm-08 and 308Win. And you know how much Americans like out of country sourced products.

Reloaders will not buy a plethora of hedastamped brass, they'll neck up 243Win/260Win or neck down 308Win/7mm-08 ... this was evident in Australia with 338Federal and 358Win ... I don't know anyone with a quantity of headstamped 338Federal or 358Win brass

In a Model 7 or Winchester Featherweight with light contour 22" barrel, or a Tikka T3 ... I'd be all over one like a rash.
Cheers...
Con
PS: The 338Federal whilst 'still-born' to some degree is an amazingly efficient performer. I correspond with a few local shooters that use it and all report favourable outcomes despite the lack of recoil and blast ... even in lightweights like the T3. Animals taken have included scrub cattle, camels, small, medium and large deer, pigs, goats etc... When you get over the 'awe' at being pushed by a 338WinMag and having your ears hammered to see 4 feet of your victim in the air when you've recover from the recoil ... the virtues of the 338Federal start coming out when the very same animals are being killed just as well without the fuss at the gun end. grin The 358Win is exactly the same ... i know of three family members hunting the same animals over hounds with 358Win, 35Whelen and 338WinMag ... the 358Win in a BLR with 200gr Hornady spirepoints is the kids starter rifle, but over the course of time its equally as effective as the larger cartridges but there's no shock and awe and bravado in shooting a pea-shooter like a 358Win. grin