RE: 280 takeoff
In my humble opinion, the .280 Remington was overshadowed by the subsequent introduction of the 7mm Remington Magnum, which came out not too long after the .280. In those days, people bought things that had "magnum" in their names, even if they weren't much of an improvement. In addition, Remington chose to use the .280 in slide and semi-auto rifles, and consequently underloaded it somewhat. The 7X64 Brenneke is almost the same, and has been very popluar everywhere on earth but here for almost a century. Yes, the .280, most especially if handloaded, is better than the .270 Win., and we know how good that round is!!
Larry