Originally Posted by
Ridge Runner
did the bullet have marks from the rifling? adjust your crimp
RR
I would try and cycle a few mags full through the gun as previously suggested.
But it also appears to me that your crimp isn't sufficient. If your first and second round went off and cycled the action OK, with too light a crimp your 3rd rounds bullet likely moved out of the case from the recoil of the previous 2 and when fed into the chamber the bullet came in contact with the rifling just enough to appear to be in battery but couldn't fire.