I am using a barcode scanner to scan QR codes into a field. When I scan them using Adobe Acrobat Pro DC they work correctly. When I use plain old Adobe Reader the scanned bar codes are truncated.
Sorry for the delayed response and inconvenience caused. As per the description above, when you use Adobe Reader, the scanned barcode in a PDF is truncated, is that correct?
Please check for any pending updates of Adobe Reader from help>check for updates, reboot the machine after installing the updates and see if this brings any difference.
Navigate to Adobe Reader's preferences from Edit>Preferences>Page Display>Rendersing>Select "Smooth images", "Enhance Thin lines" under Page Content and Information>Select "Show large Images", and "Show art, trim and bleed boxes" and see if this brings any difference.
You can also refer to the following Adobe article PDF barcode form fields
Have you checked with Acrobat Pro DC? What is the dot version of Adobe Reader installed? To identify refer to Identify the product and its version for Acrobat and Reader DC
Is it a Mac or Windows machine and what is the version of Operating system installed?
Is it possible to share the PDF file with us so that we can check it at our end? To share the file, please use Adobe Send feature, upload the file, share the link to files via private message only, How Do I Send Private Message
Let us know how it goes and share your findings.