I have a Mossberg 930 Field model that I took it out this past weekend for some trap shooting with some first timers. In the past, I would just go to Wallyworld and pick up the 100 round bulk pack of Winchester Universal and the gun would always gobble them up and run flawlessly. This time when it came to buying ammo, I saw they had individually boxed Federal shells priced reasonably since they were out of my usual stuff and I picked up 200 rounds since I had someone else using my gun as well that day since they didnt have a gun of their own. At about midway through the day, I noticed after a shot that the Federal shotgun shell would seperate ripping the hull apart at the base from the brass when extracting, leaving the hull in the barrel and the brass sitting inside the chamber just bouncing around. With the bolt open, I could just reach in and slide the hull right out but it happened about 6 or 7 more times before we left. Is this a common issue with these shells? Could the gun have been running too hot or too dirty with both of us shooting it? Something else I should be aware of? I always disassemble and thoroughly clean my guns after each outing and everything seemed to be running fine otherwise.