Having to find the ammo at a local gun store for a bastard caliber can be a pain sometimes, having a .340 Weatherby Magnum taught me that.Gun nuts are always looking for something new. Rounds like the 30-30, .308, and 30-06 are sooooo old, boring, predictable....and effective, and they are always available at the ol' mom and pop country store.
If I ever take up deer hunting again, that new-fangled .260 Remington looks like the ultimate...but that boring old .308 or 30-06 will knock down anything on this continent, except for being a little iffy for Alaskan Browns.
The .264 (6.5mm) caliber really "stacks" it's momentum. It's a long bullet in a particular weight. Sectional Density in spades. Truly a crossover varmint to deer round with proper bullets.
This is why the 6.5 JDJ is one of the most popular/desirable Contender pistol wildcat rounds out there.
The 260 finally brings an Americanized 6.5mm (necked down 308 Win, necked up 243 Win) in the medium power range to the table.