New build, jammed round in chamber - need help

[VASCAR2]

And after some investigation, I've found this which might well be a big part of my issue:
http://bulletin.accurateshooter.com/2014...artridges/

The picture in the thread you referred to showed the bolt going over the head of the cartridge case. This issue is usually caused by insufficient gas or a bad mag where the cartridge isn’t raised fast enough to be pushed forward by the closing BCG. I suspect you don’t have the gas block opened enough, with insufficient gas the bolt carrier doesn’t go back far enough to get the required momentum from the buffer spring to force a round into the chamber. On a tight new build a cartridge can be difficult to extract.

The ejector mod is a good idea and I did this mod to one of my bolts and helped.