I have a 1100 20guage that is giving me fits. When I try to load shells into the magazine tube, they go about half way in and stop. After trying a few times they go in. It feels like it's hanging on something in the tube, but it's not. Plug is out, new spring, new follower, tube is not dented and is clean. Just started doing it this year, bought the new spring etc trying to fix it, but no luck. Cycles fine, just hits a solid wall when loading till I continue to push the shell half in and out till it finally goes in.

Any ideas?