I owned two and had bad jamming problems with both of them,and recently got rid of them for a benelli.On one the plate on the bottom of the bolt had a screw that held it in place worked quite well,the other one I had did not have the screw and was not drilled for one.With magnum loads the damned firing pin would come out of the bolt and jam the gun solid.It happened after a shot on a bear that was tearing up my camp and I would never rely on one again.It always worked good with 2 3/4 birdshot loads.I had to replace the firing pin twice as it would get bent badly when trying to cycle the action after it jammed.When shooting at birds or targets it was a bit of a piss off,but that bear ruined me on the defender.Like the benelli fine so far!