The ASA on my AT-10 spins!! I can't seem to get my stock to unscrew as a result...does it need to be sent to ATS for repair, or is it beyond help and I need to purchase a new ASA assembly?
Send in the rear housing for repair. As you are spinning the ASA the screw that holds it in place is loosening. That means the entire ASA can come off. Figure somewhere around $35 plus shipping to repair.
That's the easiest way to do it. If it's damaged bad enough the housing may need to be replaced but generally if it's the first time you've spun it free I can fix it up.