I bought a Fabarm L4S initial hunter two years ago, and it was jammy right away. Everyone always says, "clean it good and shoot a box of heavy shells through it" like this is a cure-all. Sometimes it works, and sometimes it doesn't. You are right to get on this right away, get it looked at by a good gunsmith, and if problem persists get it in the warranty process as soon as possible. In my case I cleaned the gun a bunch and shot it a bunch and it didn't matter, it had to go back to fabarm and they hammered on it there and got it in proper working order.