I have a flat bolt Ruger 77 in 6.5 RM and it is obvious why Remington/Peters only loaded 100 and 120 grain factory ammo, the COAL limits of a short action magazine. If a key aspect of the 6.5 Creedmoor's superiority over the the 260 REM is that its shorter case length allows for longer/heavier VLD bullets to fit into short action magazines better, the same goes for the 6.5 RM. If you're going to build a 6.5 RM on a long action in order to eliminate the short action COAL limitations, why not opt for a cartridge that has the same approximate performance potential while being much easier in almost all aspects, the 6.5-06?
The 6.5-284 has approximately the same case capacity as the 6.5 RM and while brass is easier to come by, it has the same COAL limitation issues in a short action.
