I'm a noob to just about anything firearms related Yesterday I bought a 12 ga Mossberg 500 just to learn the basics of scatterguns. It's weird. I load the tube, pull the fore stock back, look into the receiver and the shell's sitting in there loose like a duck in a pond. I could blow it out with strong enough breath. Move the fore stock forward and sure nuff the shell chambers. I mean there's no mechanism that holds the shell snugly prior to being chambered. I'm used to the semiauto pistol operation where the round is always held snugly either by mag lips or by the chamber walls. Is this kind of a pump gun feature I shouldn't even be asking about?