I was duck hunting this morning, and had a flock of mallards fly in. I shot the first one, and as I racked my shotgun I noticed the second shell didnt load but stove piped. I pull it out with my fingers and see that my retractor didnt grab the empty shell. Turns out the shell expanded so much that it was stuck. It took any chance I had of shooting antoher bird away for today. I was shooting a mix of kent #4's which cylce fine, and a handful of Winchester xpert HV steel shot #2. Well I only shot one and had that happen, so I dont plan on using the rest of them. When I got home I used my cleaning rod to push the shell backwards in order to get it out of the barrell. I had to use a lot of force to move it, and have never had that happen before. I checked my barrel, and it looks good, my retractor looks good and doesnt have any damage or buildup on it. Do you think it was a ammo issue, or a sign of things to come on my gun?