printing noaa charts from .pdf

[Silver_Surfer]

hello,
wondering if there is a setting i'm missing when downloading .pdf and printing using a large format printer.
no matter what scale i use or mimic the size of the original(ex. chart 18020 752.4mm X 1013.8mm), the 6inch/152mm line along edge of chart is shorter. just about a 1/4"
is there a printer properties setting i'm missing or is it not possible to print correct scale from the .pdf's off noaa's chart locator?
thanks