Thread: Short fatties vs long slender ones...

One of the members just posted this: "short magnums in general,... don't mind a short barrel due to their short powder column".
Now I know that the case capacity to bore ratio allows a cartridge to be more efficient (less case capacity/powder to bore size = more efficient).
But what if you had a long cartridge and a short, fat cartridge that both had the same case capacity ie 6.5x55 and 6.5 Creedmoor or 284 Winchester and 280 Remington (close enough for our example).

Does a short, fat case design help to reach full-potential in shorter length barrels compared to a longer case design of the same amount of powder?... or doesn't it matter?

NOTE: this is only taking into account the case design NOT that the shorter cartridge allows say 1" shorter barrels due to the shorter action required.