For all misfires I would ask why if it was me? Would get my gun checked out for sure. Also, try to get one back to factory so product can be checked. Any product could be defective. Over thirty years no misfires hear. Just shot a box at range...bang every one. Is there a lot# on box. I have notice two different shells. One shell is crimped near the point and one is not. My gun shoots the ones that are not crimped more accurate.