Downloading a PDF artifact using Chrome (17.0.963.79 m on Windows) the HTTP header for the last partial entity-body sent back by Jenkins contains:
Content-Range: 2613923-2646691/2646691\r\n
I believe this is wrong according to http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.16 . I believe the last range should be 2613923-2646690/2646691, because the numbers are 0-indexed.

I'm not sure whether this is caused by this or is a separate issue, but Chrome keeps requesting the same last partial segment and Jenkins returns the same one in an endless loop. Thus Chrome is stuck loading the PDF at 100% in the endless loop. This only happens with the Chrome embedded PDF viewer. The file downloads correctly with "Save as".

Update: It now appears that the content-range unit "bytes" is missing from the header.