Surf, seems as though your OP is oriented toward the "what rifle should I buy?" questions. And you mention knowing about the shooter as being important. Ok, what rifle should I buy? First thing you need to know about me is I have a wife. Purchases need joint approval. She has ideas for any extra money the household has. A new gun isn't a priority for her. Ok, she'll let me spend $500. She won't be happy when tax takes it to $580, but she'll adjust to that. A purchase price over $600 would be a big violation. So, from the husband's point of view, it is "What can I get for X dollars?" Knowing full well that the purchase has to be made before an unexpected car repair, or need for a new kitchen stove, changes the wife's mind. Now about the husband. I'm not a soldier, not LEO, don't live in a high crime area, don't often go to the bad parts of town. I can hunt just fine with my existing $400 scoped .30-06 bolt-action. At the bench, it only shoots 2" groups at 100 yards. Most hunting shots are only out to 75 yards in the woods. Off-hand I can hit a 6" circle reliably at 100 yards, so I figure I'm good to go. For protection, I've always got my Glock 26 on me. I'm casual IDPA, qualified as Marksman. I figure I can shoot better than 90% of the people I see at the range. If Navy Seals come after my home, I'd be in trouble. But otherwise, I feel pretty confident I can protect my home if some local thief decides to become an armed thug and threaten mayhem. I've got 30 other guns of various types, rifles, pistols, shotguns. Some from when I was a kid, some specifically for the wife, some for teaching. Runs from bird hunting to .22lr bullseye at the local club. Happen to do some NRA pistol instructing to newbies, and help people get their permits. For $500, might find a good deal on a Savage 10FP .308, with a cheap scope. Did that, and got .75" 100 yard groups. A different year, another $500 limit, might decide to get a Saiga 16", 7.62x39, sidemount detachable scope, kept in sporter stock. Cool gun, fills a potential home defense role if needed. Newbies like to shoot it too. 300 rounds a year, no jams, clean once a year. Ok, how about a $1,000 rifle? $1,500? Come on wife, I've been good. Maybe a bulls eye pistol, S&W 41. Maybe a Colt Python? Maybe a Glock 10mm (and not spend so much)? Or maybe an AR? Ok, it is agreed, $1,500 is the limit. Wife on board with it. Husband doesn't necessarily want to spend all that because he's also thinking of getting a couple dirt-bikes for him and his 7yr old son next year (will be 8 then). Still he's always kinda wanted an AR. Has an Interarms Mark X scoped .223 bolt that can't stabilize 62gr, but gets 1.25" at 100 yards with 55gr soft point Black Hills. Good light woodchuck gun, for humping in the fields. Has delivevered quite a few off-hand head shots over the years. Would be nice if the AR could shoot the same ammo. Don't need to scope the AR, but maybe would. Not sure. Maybe go old school with iron sights. Maybe a 3x9 scope. Maybe a red dot. Short M-4 style or longer A2 style? Don't know. Kinda like the old Vietnam War era look of the M-16. Should the AR look like that? Mainly will use at the range, or in the back yard. Live in the country. Maybe hunt varmits, but already have the bolt .223 and a lever .22mag for that. Maybe home defense, but there's not much need for that. I keep a Beretta 92, 15round mags at the ready for that, in addition to my carry gun so it is ready for the wife. Also have that Saiga ready to go. The AR is more for just wanting an AR, for the fun of shooting it. Can the AR shoot 5.56 ok, and still be ok with .223, especially 55gr soft points? Never ever jam? (That was one reason for getting the Saiga). Will it be capable of less than 2" groups at 100 yards out of the box? (if I scope it, or get real good with irons). Even the Saiga does 3.5" in my hands and cheap Wolf ammo. Could the AR also handle heavier ammo if I wanted it to, without keyholing like my Interarms Mark X does with the 62gr? Will it take all kinds of mags easy? NY is a ban state, so I can't be too choosey about the pre-ban mags I might find. Oh, would it be legal for some sort of CMP match? Not sure what clubs do that, but maybe I'd look into it. Heck, maybe my own club does it. I've been more involved with pistol. So, I don't know if I'm typical or atypical, but this is how I'm approaching the potential buy of an AR. And a little horsey on the side probably gets bonus points because while I've got 5 S&W in my house, I don't have any Colts. Cool, I'm a category A+!