I am still very curious what caused the problem.
That makes two of us!
If the gun isn't tight neck, makes me think that maybe you got a bad batch of VLD's (perhaps a void between core and jacket on some of them)??
It's very suprising to me that brass and neck tension alone could actually squeeze or swedge down a bullet, unless the bullet is too soft or bad from the beginning. If the brass neck will swedge it, then the rifleing would probably destroy it.