any ar experts out there? bolt wont stay open with empty mag inserted

[doggin coyotes]

Since this was brought back up,

jimmie, did you ever figure out the problem or cure or what was going on with the rifle??

 

[Luckytrey]

I built a lower once that did this same thing. There was trash in the hole the spring goes into for the bolt hold open. I could make it stay open manually but not on its own. Take the roll pin out and spring. Get a small nail or paper clip and stick in the hole and scrape around a little bit to see it the is compacted debri in it. That is what fixed mine.