I have a few questions--I apologize if I'm repeating old questions, but the AWB expiration has me hankering for an "evil" weapon. First, let me preface this saying I'm looking for an AR in .223 with a 16" maximum barrel length. I want a handy carbine flat-top that is as reliable as possible, very accurate, and can do well varmint hunting or as a self-defense weapon. I'll probably mount a red dot or scope with BUIS on it. My first question is do some gas blocks affect accuracy more than others? I'd like some flip-up unit like GG&G's modular front sight, but I'm not sure how it affect accuracy. Secondly, what is the best, euphimisms aside, "people killer" combination in bullet-type, weight, and twist rate? Also, can this same twist rate accomodate rounds that would be suited for various types of hunting? Finally, for my purposes, would I benefit from a stainless steel barrel? I've heard they are more accurate than chrome-lined barrels, but I don't know if that's a wives tale.