I have a home build I built last year. It keeps having feed issues. Either it tries to feed a new round without the brass fully ejecting about 1 in 10 times or after a few rounds it seems to cycle, but nothing when you pull the trigger. Pulling the charging back enough to check to see if a round fed and releasing the charging handle and it fires another round. Ammo shows light strike dimple on primer. Happens about 1/3 of the time with multiple brands of ammo.
I did find some of the trigger pins had started to walk out so I replaced them with some anti-walk pins. I haven't tested it after installing those. I also changed out multiple parts in the BCG. (BCM extracter spring upgrade kit, BCM firing pin, cam pin) I haven't had a chance to get to the range to test those changes yet.
The upper is PSA, the lower is TN Arms. I tried different magazines.