Mine doesn't sit flush either......and has the gap at the rear of the ejection port directly in front of the extractor. I have only shot 65 rds. through mine thus far, but it shot perfectly! I will continue to monitor it....but if it shoots like it did the first time out, I will not give it a second thought. Just out of curiosity, other than the visual aspect, what kind of functionality issues does/or could this imperfection pose?
Take care, Mike Arnold