I can give my two cents, besides the spring was it working before or was it always having an ejection prob, I had a problem once with my brass catching because it was new and maybe a had a little lager diameter and the defiance bolt face has very tight tolerances where the brass would catch sometimes if I pulled the bolt back slowly for some reason, is the plunger flush with the top and have force behind it would indicate that the plunger is working correctly if its slightly 1/16-1/8") under the top face of the bolt would indicate their is a problem with the plunder, try taking a spent brass and put it into the bolt face out of the action and slowly release the presser if it sticks I would bet its the brass is a little large on the out side making too tight of a fit with the face diameter