Okay guys, I've owned my AR (Colt LE6920) for about a year now. I've actually shot it very little, but I keep it cleaned and lubed. I work for the department of corrections and am an armorer, but we use 870's and Mini 14's. I just don't know the AR platform as well as I want to. What is the best, most cost effective, way to learn it? Like I said I work for the state, and have 3 boys, money is always a concern. Running off to a class is out of the question, at least at this point. I want to learn this weapon and be a fan for life, that includes being able to replace parts if need be. Any suggestions?