Kind of thought this would have been mentioned by now, but you need to check upper to lower fitment. With the Plum Crazy lower it is possible that either the fitment was bad to begin with or the rifle has been broke down enough to cause the lower to fit more loosely than it should. Upper to lower fitment can cause major issues with accuracy in an AR-15 platform. But as mentioned before check the barrel nut to unsure it is holding the barrel tight.
http://www.youtube.com/watch?v=IgaTzNLTRJI
He talks about fitment at 9:58 in the video.
My best advise would be if he is really wanting a scoped AR-15 rifle is to ditch that one and buy one of quality. Never anything with a polymer lower.
http://www.youtube.com/watch?v=IgaTzNLTRJI
He talks about fitment at 9:58 in the video.
My best advise would be if he is really wanting a scoped AR-15 rifle is to ditch that one and buy one of quality. Never anything with a polymer lower.