You probably know this. But before pushing anything down the muzzle end of the barrel make sure the receiver is separated top from bottom and try pulling like hell on the charging handle. Could be a jam in the lower half causing this.
Are you REALLY, REALLY SURE it's a empty case in there?Can you tell us what type ammo it was? Surplus? Hand load? Had you used the forward assist / turn a little jam into a horrible jam button? (not your fault! Stupid thing IS there!)
If you do come to this, I'd put a cleaning rod in the muzzle (lower half of receiver off), put the handle end of the rod on the floor, and gently bounce the rifle on the rod while squeezing the the release on the charging handle. GOD, I HOPE YOUR RIGHT ABOUT THAT BEING A SPENT CASE IN THERE!!!
I hate AR's. Damn things are just
way to over engineered (coming from an engineer)! Seen the Youtube video of one blowing up on a guy trying to clear this type of jam?!?
