I've searched the sight and found no answer. I've noticed that the extractor slot is cut in the "barrel block" but not in the barrel. How does the extractor work if it can NOT reach the round. I know you want part numbers but I can not find them here or in my owners manual.
This is what is beleived to be the weakest part to the gsg design just from the amount of problems in this area. The extracter has the round once chambered the ejector snaps it out of the extractors clasp when the bolt cycles. When and if you bolts come loose around the barrel or any other part of your weapon stop shooting and loctite and tighten up. This is what I think and not fact! contact chris from ati or ray and see if they can get you one if you need it.
Here are the part numbers you might be looking for...
Extractor Spacer (2-Req)400.40.23.1
I hope that helps.
I found the problem. The barrel retainer screw had loosened. I realigned the barrel and it did fine. Anybody know if there is a specific tightness or just hand (hard) tight?