I love my 9mm shield but have found it difficult to rack . Many threads mention this issue without any resolutions. I was ready to trade it in when my bf offered to take a look. He found it to be sticking and to confirm his suspicion he reassembled and racked it without the guide rod/spring and found the lower part of the slide rubbing against the polymer frame just below the guide rod. After filing it down, the slide now moves smooth enough so I can rack it.

Interesting. Can you post pictures of where he filed the frame?