The 6.5x53R Mannlicher is a rare and somewhat expensive[1] cartridge. I liked the specification, but I wanted something cheaper, so I used .303 British brass run into a .256 Mannlicher die, to created a 6.5x54 rimmed. Since the rifle I was using already had a bolt and magazine set up for .303 it was a reasonable solution.

The .256 pushes a 160 grain 6.5mm bullet at a modest 2150 fps. Wimpy by modern standards, but I liked the ballistics of the 6.5mm bullet and didn't need the recoil of a .260 Remington or 6.5 Grendel just to punch holes in paper.

[1] well, probably not by double rifle standards...