I'm not surprised you're looking for a firing pin...
I've got 3 brothers and 2 of them own AB-10's.
Both broke firing pins the same day at our local indoor range...
Luckily, at the time, Intratec was still in business, and replaced both firing pins, no questions asked...
I'm pretty sure my dealer had a bunch of extras made at a local CNC Machine shop...He's still got a couple AB-10's for sale...(can't give them away)
I'm not positive they were for AB-10's,but pretty sure..
You could give him a call at...
THE GUN GALLERY
(610) 779-4160 ..ask for Jay (owner)