Home Forums Hunting & Shooting AR and Tactical Rifles Little Help Here (diagnose this group?)

Put it all together yesterday. All together means the only rear sight available locally which was a plastic bodied folding rear from mag-pul.

Even at 25 yards it shot Ok for a few shots then started opening up quickly. It is a pencil barrel, 1 in 9 with federal m193. Rock River lower with kind of a sucky trigger.

Here's one of my typical 100 yard groups.



And one of the rifle



Anyone care to guess whether the barrel is heating up and shifting poi? Or is the kinda springy folding rear aperture shifting? Or am I just helpless at shooting?

Think I'll get a better rear sight headed this way.