I bought a new 11-87 light contour 12 ga. last Dec. Only shot it a couple of times with buckshot maybe 10 times, no problems. Haven't shot it once till last monday, opening day of dove season. After about 5 boxes of shells it started jamming about every 5 shots. Went home and thought it might need some oil. I oiled it good, and it worked fine for the rest of the day. Today started out fine then after about one box it started again, then just stopped ejecting. The ejector slide sometimes comes back just a little then i have to pull the slide back to get the empty shell out. What in the hell is going on ??