Well I finally had a head separation in my AR the other day. Luckily it happened at a guys house that has 40 yrs experience working with firearms. He showed me a quick way to get the broken shell out of the chamber. He used a .22 cal brush and ran it down the muzzle past the shell, then pulled it a little ways back into the chamber/bore. Just enough to get the bristles pointing back towards the breech. He then popped the shell right out by pushing the rod back into the breech. I was a little skeptical when he told me how to get it out but it worked lickity split. Sorry if this is common knowledge but I thought I would pass it on for anyone who did not know already and was looking for a solution before they damaged their firearm trying to get the broken case out.