I was at the range today with a friend who was shooting his AR-15 and I was shooting at the next station over. We were shooting at 100 yards. He was trying to hit the bullseye, obviously, and couldn't group two round any closer than 6 to 8 inches in every direction. This AR is the same AR that I had sold him. The scope is mounted correctly and there were and are no problems with the rifle. I shot it and hit what I was aiming at. He said the scope sucked and there a couple of times I thought he was going to throw the scope or the AR with the scope on it. He finally got so pissed off, he quit shooting. He had made the comment to me that he would let me sight it in for him but then it wouldn't be sited in for him. My question is, even I know the answer: If one person sites in a Scope will the scope be sighted in for another? He argued that it wouldn't be. I have always had to sight in my dad's rifles for him because he doesn't use the 1/4 moa correctly with the squares. If it's off an inch, he turns it "some". Once I have sighted it in for him, it's always dead on. I have also shot more rifles than I can count that belong to other people and they are always dead on also providing I'm at the same distance they were sighted in at. I wasn't going to argue with him about it for the simple reason I didn't want to argue. I know he was upset and he had even shot my target with a couple of stray bullets when shooting at the target next to mine.

Below is my Silhouette and his 5 spit target.

It may not be perfect but it will be close. Friends of mine have used my rifles many times and hit close to where I tell them it hits at a given range. it just sounds like it is an operator issue to me. Some people are naturals some aren't. Practice helps some, others do better with rocks. Trigger control, breathing, stance and flinch play big roles in accurate shooting as I'm sure you already know. If he is inexperienced some training may be in order.

I totally agree about the training! The weekend prior there was two instances that came up. Once where I could have been shot and the other where he shot my sandbag he had sitting on the back of the pickup I was sitting in. He's said numerous times he wants to go deer hunting with me some time so I finally decided to ask him if he has ever taken a "Hunter Safety Course". He said no. I told him that if he ever wants to hunt here or an most other states, he'll have to have it. His reply was that he didn't need a license in Arazona because he's part Indian and gets to hunt on their land. My whole point was that he needs to learn the safe way to handle and shoot firearms. I don't care so much that he shot my sand bag and almost shot a hole in my new pickup. Those things can be fixed or replaced. My life can't be.

Be careful around this guy and guns he definitly sounds dangerous. Try to teach him some things w/o making it to obvious and if he resists then i would not shoot around him again. Your life means more than his feelings. I would not go hunting with this guy for any reason until he learns some things. The only consolation is that if you were in the field and he mistook you for a deer the shot might not kill you.

if the rifle is sighted in, its sighted in; doesnt matter who is shooting

it sounds like a problem w/ the shooter........

Your friend needs to take some basic marksmanship course, from his target it looks like he needs to learn trigger disipline.
He's going for that perfect sight picture, and when he gets it, he's yanking the trigger, rather than slowly pulling it.