It is a somewhat confused copy or slightly altered remake of the 7x64 Brenneke, which was invented popularized a few decades before in Germany. 7x64B is considered a first rate standard versatile big game cartridge in all of Europe, Africa and much of the rest of the world. Remington couldn't decide if they want a low pressure round to use in semi-autos, or a long range light bullet medium game cartridge, or a metric designation, and they fumbled their marketing effort several times.
It wouldn't exist if Americans weren't so adverse to anything Metric or invented in a foreign country. The 7x64 does it all for common North american game, and the .280 does too, case capacity is almost identical, case shape is so close you'd have to measure with calipers to tell them apart.