My experience has been: When the bolt doesn't fully close something was wrong with the case/bullet. Pounding on the FA generally made it worse and it took a rod down the barrel to clear or wedge a screw driver between the ejection port and the bolt to pop it out. You are better off pushing the mag release and dropping the clip then grabbing the charging and ejecting before it's really wedged in there.
We had days in the military shooting 1000's of rounds being evaluated as a team on knock down targets, bullets got dropped loading clips. Clips got dropped on the ground in what ever environment we were in. I even had the little clip come off the door and I didn't have a way to fix it in the field and had to tear it off. I had a forward assist push button pop apart and had to monkey with it to repair later. The first time I saw the slick sided unit I thought what a great idea.
I have all extended take down pins, charging handles, buttons...
If I was having Amby problems like the poster I would just get rid of the door!