I’m going to record my AR-9 trouble-shooting process in this blog post so that maybe someone else can glean some insight into all the things that can possibly go wrong, and how to fix them… because I lived through them.
I bought a DDLES “Glock mag” AR lower from Gunbroker once upon a time because that was the hotness like five years ago, and hard to get hold of. It was a smoking deal; based on the person’s other sales item and lack of engraving on the lower, I suspect they had an illegal SBR they were parting out in an attempt to make it go away. I dutifully filed a Form 1 on it, waited G-d only knows how long, and bought a cheapo PSA upper to put on it – I think it was 10.5″, whatever it took to get it across the magic 29″ OAL floor we have in MD.
It was a terrible performer right out the gate. It didn’t eject right. It didn’t cycle reliably. It tore cartridges in half. But, last night, after months of work, I got it working. How? Read on.