When you say it sounded different than all the rest, my first thought is you may have had a squib. Then when you say the next round was difficult to chamber it makes me think the next load was cramming into the projectile left from the squib. I would fully inspect your bore after that scenario. You may have gotten extremely lucky and the round you had this experience with actually pushed the stuck projectile out of the barrel. If you ever have a round that sounds different than the rest. STOP, unload the firearm, and fully inspect it before continuing firing.