Originally Posted By airborne118:


Need help diagnosing dangerous malfunction — PSA AR-9 (Glock-mag) burst fire & ruptured cases

Hey all,
Looking for some input and advice before I send this rifle off for inspection.

I was out shooting my Palmetto State Armory AR-9, Glock-mag version, using 115-grain factory 9mm ammo (standard range ammo, not reloads). The gun unexpectedly started firing in bursts (2–3 round strings per trigger pull) and I had several ruptured casings, one of which blew the magazine out of the well.

Here’s a photo of one of the cases:

Needless to say, I stopped shooting immediately. The pistol is unloaded and will not be fired again until a gunsmith checks it out.

Has anyone seen this type of failure before on a PSA AR-9? I’m trying to understand what might have caused it before I contact PSA for warranty inspection.

I used 115G federal and 124 Privi, and the barrel is 10.5 Inches.https://ibb.co/zhbZH3HH

Possible issues I’ve been told to look into:
•Overpressure ammo or defective case
•Unsupported chamber causing case head failure
•Premature bolt movement (bolt mass / buffer weight too light)
•Hammer follow or disconnector malfunction causing burst fire
•Out-of-battery detonation
•Magazine or feed-angle issues
•Barrel obstruction or damage

If you’ve dealt with something similar, I’d appreciate your insight on:
1.What to check visually before I ship it to PSA or a gunsmith
2.Whether PSA has been responsive with issues like this
3.What buffer/bolt setups people have found most reliable with 115-grain ammo

Thanks in advance — safety first, just trying to gather some background info before I send it in.

?

Originally Posted By PalmettoStateArmory:


Please PM me your order number and I will get you taken care of.

Thanks,

Josiah

Originally Posted By jaqufrost:
The first thing I would look at is the disconnector and disconnector spring.

Anytime you're getting burst fire those jump to the top of the list for examination.