So here is a new one for everyone to laugh at (or cry)....
During a range session today, I experienced a failure I had never seen before, heard of, read about, thought could even happen....
During a string of slow aimed fire off a bipod and rear bag the rifle failed to go into battery, I the round in the chamber and attempted to cycle the bolt with no joy. The sound was odd and I felt it was wise to stop and get it back on the bench to diagnose the failure. I was done for the day anyway, glad I stopped and didn't try to force anything.
The Bolt would not seat into battery, I guessed based on where it was making contact that there was either a blown primer or a rock stuck in the BCG where the locking pin goes through the bolt inside the carrier that was stopping the bolt from being able to slip back inside the carrier. This presented a problem where I could not open the upper receiver from the lower as the bolt was back just far enough it would not clear the buffer tube joint of the lower. At this point I needed to get the BCG out somehow (and forgetting that I owned a barrel vise) I did not want to attempt to get the barrel nut off without using an action rod to risk destroying my upper or barrel. Came to the decision to cut the back half of the carrier to get the bolt out. This was a budget BCG anyway so not the end of the world to destroy a $60 item to save the upper.
After getting the BCG cut and removed to my surprise the culprit was a popped primer that had magically gotten stuck inside the gas key.. yes you read that correctly, inside the damn gas key. It is a near perfect fit (I do not recommend testing this yourself as it will take a lot of cursing and some time to clear). The gas tube looks fine, glad I didn't try to hammer the bolt forward or I likely would have destroyed that too. But something for you all to put in the back of your minds as a possible point of failure. but really, what are the damn odds of this one!!!?? Ugh.....