If the empty case stays in the bolt it might be under gassed/powered. In other words it sounds like it’s short stroking. Load one round and see if it locks back on an empty mag.
No it was fine with running one in the Mag and then it locking back. It’s only when more than one that is brass cased in the magazine that it acts up.
No worries though, I ordered a new gas tube and gas block for it.
