Long story short, my son owned a DPMS Panther AR type rifle. He moved to Buffalo and basically gave it to me as it is not allowed in his new home. I haven't a clue how to operate one and too embarrassed to go to the range and fumble around with it. He has a new Burris FastFire III on it but its never been sighted in. Suggestions on how to learn about these? I'm probably the only member on this forum to have never touched one.