Scaling to 97% for codabar to be scannable

I used Adobe Reader XI to print label to Zebra 500 EPL thermal printer with label size 4 x 6.75 inches. I used actual size but the printed codabar was not scannable. The codabar can only be scanned after I used Custom Scale 97%. I used Foxit PDF Reader and got no problem to scan the actual size codabar. Any solution not to do any scaling for the codabar still be scannable? Thanks.