When it does eject with that load, where does the brass land?
apparently in the chamber
If the rifle is ejecting factory ammo at ~3:00, it's working correctly. Either change the powder or the load. Brass, primer, and mostly your chamber can all be factors in speed and pressure. Not every load you try is going to work in terms of accuracy and function.
Try some varget, XBR-8208, CFE, etc.
