These rifles have two barrel wedges and quite often, one will have pressure on it and one won't, so it falls out easily and gets lost. Take the barrel out and peen the slots closed just enough to grip the wedge.
Thank you for posting this I'm going to check mine out tonight. Good Info!
And everyone is right about a GPR, these guys here recommended one to me, and well the things are a put a ball in the SAME HOLE kind of rifle
! I love the big old heavy beast!