Have an original Armalite AR10 A2 and it has an issue. It fires and cycles live rounds fine. It is when you say.... fire 3 rounds and put the safety on take the mag out and try and pull the charging handle back to unload the weapon, it will not eject the live round. It is like frozen. I have to take a piece of wood and a mallet and whack the charging handle to exert enough force to get it to eject the unfired round. The ammo is std lake city ball ammo, nothing special. Any thoughts? It cycles live unfired rounds with the charging handle fine. I am puzzled. Thank you for any help.