Hello from Arlington, Virginia. This is my first time in any forum but this looked like a terrific place to learn, so here I am. I've always been interested in historically significant firearms, so about 14 years ago I bought an Armalite AR10-A2 because I didn't want a .223. I ran a few rounds through it and put it away but have recently decided to try to learn more about it. (That and another purchase made last month, a DPMS AP4). I'm motivated to learn and I hope I won't irritate anyone with dumb questions. Thanks for having me.