So, I picked up my 300 dollar 870 express, and after shooting about 15 shells of 00 buck thru it, the next 5 would not shoot. I loaded them in and cocked it, nothing. Looked into the bottom of the reciever and there was a shell hanging out in the right spot, but i could push it back. I.e. The mag tube spring was not pushing against the shells. I ended up taking the shells out and then turning it up side/shaking it and magically it worked. Any ideas? Return it?