did you check the pump's slide rails? they may be bent or cracked? DO take out the parts and check for knicks, dings, bent parts, and burs.
Yes its all smooth i think the chamber that the shell actually sits in while being shot needs to be smoothed cause the guy that had it before me didnt clean the much if at all... fyi i hate that im a firm believer in keeping your guns clean at all times even if u only shoot it once clean it