JFSNDBT

I recently bought a new Legacy and took it out to the field to shoot. I had problems with adding shells to the magazine tube after firing/ejecting. Any ideas - does it just need more "breaking in?" I loaded 1 shell up top and 2 in the magazine tube. I shot once - the shell ejected, and I tried to stick another shell in the tube (to have a full 3 in the gun). The shell wouldn't go in - it didn't give me the feeling like when the tube is full - but more of a tightness when I pushed the shell halfway in... I backed all the shells out and loaded them again - like I did initially and it worked fine. Any thoughts?