By the way, where is that famous chart for AR rifles? Is it even currant anymore?
I'm afraid that I am unaware of the chart that you are speaking. if you are refering to the one that shows where certain companies contract to have their recievers made I'm afraid is grossly outdated. there are several that have switched fabricators and others that have been introduced since then. it can usually be found on AR15.com. if that is not the chart you are talking about then I am very sorry for adding useless information.