A friend and I were discussing guns, mass shootings and gun control at work today. Naturally the AR-15 became the focus of the conversation. In this conversation I stated that I had recently acquired a Springfield Armory Saint rifle to add to my collection which consists of a few M&P 15 rifles and a Sig Sauer 5.56. My co worker lumped my rifles together as all being AR-15s and this is where disagreement ensued. I argued that any rifle that was NOT a model 15 made by Armalite is NOT an AR-15. He argued that all of my rifles were AR-15s regardless of caliber and that the name defines the (military) style. I have looked through the accompanying documentation for all of the rifles that I own and nowhere is the AR-15 name used. The Smith and Wessons are all referred to in the documentation as M&P 15/caliber or Sport, the SIG is referred to as SIG 5.56 and Springfield is only referred to as SAINT rifle. However, online they are all referred to as being AR-15s. Now I'm trying to confirm if I was right or wrong in my argument that i do not own an AR-15 and that AR-15 is a name for the Armalite Rifle model 15 manufactured by the Armalite Company and the Armalite 15 is the only true AR-15. Am I right, or am I wrong?