Try 'Print as Image'.
tried that it didn't work
The only way i can print is to use custom size on my page setup.
Then I have to guess what % number to pt in to fill page
This is occuring because you might have set page scaling option as "Actual Size". Kindly change this to "Fit" or "Shrink" based on your requirement.
To read more about scaling options, you may read http://helpx.adobe.com/reader/using/print-pdfs.html under Print at a different size.
This is a little late, but maybe it might help someone else. If you're trying to print a PDF from a website, try using your web browser's print feature, and not Adobe's print icon. I was having issues too. Once I printed from the web browser's print feature, I was able to correctly scale and print through the print preview window. Hope the tip helps.