I've had ARs since I was 18 and in the past few months I had the bug to build a few more. I usually run nickel boron bcgs. Well I built a RR and took it to the range the other day and got 4 rounds through it and then the bcg wouldn't fully go into battery, thus I used the forward assist. I bought a fail zero for the first time and I'm asking if anyone knows if they have a certain break in point and I just need to keep shooting to break it in as that has been suggested to me. Any feedback or personal experiences would be great.