First, you need to understand how the Auto 5 works. When the gun is fired, the barrel and bolt recoil, locked together. At the rear of the stroke, the barrel unlocks and comes forward, driven by its spring, the one under the barrel. The fired shell is held by the bolt extractor. As the barrel moves forward, it pulls away from the fired shell and an ejector on the inside of the barrel extension kicks the fired shell free and out the ejection port. As the barrel goes into battery, it trips the bolt release, letting the bolt come forward, driven by its spring in the buttstock. That raises the carrier and presents a fresh shell to the bolt for chambering.
If the mechanism is not understood, the gunsmith can chase extraction/ejection problems for a long time with no result.