Quote Originally Posted by 1168 View Post
KVP appears to use a M16 extractor. I had a lot of similar stoppages with a Faxon BCG, that also uses a M16 extractor. I tried the stock extractor spring and a Colt one on a Colt M16 extractor. Tuning the ejector did not fix the problem. If I remember correctly, using a stiffer action spring made it worse. Using lighter ammo made it worse.

Using a no-name, gunshow garbage BCG with a 9mm extractor solved my problem, and it runs like a sewing machine with any garbo ammo.
Did you try the o ring method in the extractor?