New build gas questions

[trevorbrow91]

There is a rifle length gas on it and the duramag is locking back and the brass is now ejecting at 330. I added an H1 buffer at 3.8 oz and that seems to have helped however I was not able to finish testing as I only got 6 rounds into it and the extractor broke and I have a piece of brass stuck in the chamber. Any ideas why this would happen on a brand new bolt.