My AL391 stovepipes when trying to shoot doubles. I have shot 500 rounds through it and tried different makers of shells with no luck. My son is using this now because I bought an O/U. Any idea what may cause this? I am thinking about sending it to Beretta for repair but do not know if it is broken. I have read several threads on here about reliability and how they only jam 1 out of 500, and so on. Mine isn't like that. It will stove pipe 50% of the time. It does it whether it is clean or dirty. All ideas are welcome.