Good morning. My name is ***** ***** I am happy to help! It definitely sounds like something is mechanically wrong....perhaps the action lock or similar. Obviously, its impossible for me to completely diagnose the issue over the internet.If you just bought the gun, it should still be under warranty. I would suggest contacting Mossberg customer service quickly and have the gun looked at by them. - http://www.mossberg.com/customer-service/Please let me know if you have any other questions....Jim
Do you need anything further?