Steel cased rounds, while inexpensive, can jam your AR-15 easily. Here's how you can quickly (and safely) remove them, and get back to firing at your targets.
The AR-15 with magazine loaded and ready to fire.
A jam! The chambered bullet has most likely been shot. This would leave just a jammed case, but we're going to verify that first.
First, eject the magazine. If your cartridge is wedged, you may have to wiggle it a bit to get it out.
Next, pull back and lock the bolt so its not pressing the live round against the jammed casing.
You should now have several angles from which you can remove the live round. If a simple shake doesn't work, try needle nosed pliers. Be very careful the hammer doesn't release and snap shut.
Close the chamber and try to fire the spent round. This is a safety percaution to make sure the jammed round isn't still live. If it doesn't fire, we can unjam it.
The hammer may give you a hard time when reopening, so I've found the easiest way is to brace it against your shoulder, then push down on the hammer while gently thumping down on the bench.
Like so. You may have to repeat a few times, I got lucky here on my first try.
Now we take a rod (I use one that comes off my Mosin-Negant rifle) and gently guide it into the barrel. Gently tap downward until the casing comes out.
That should be it. Back to shooting!