This could be a result of excessive recoil....broken stock through the hand, 'scope left forward as the action recoils back, so I'd first suspect the ammunition.
Is it factory from a dealer who has this from the wholesalere/importer or "factory" as in something that has come out of an auction or from someone's cabinet that has given up that calibre? Whatever I would keep any fired cases, unfired ammunition and, if you think it useful, have it looked at and shot by the Proof House for a report on it. If you intend to make a claim for replacement stock.
I'd also as a matter of commonsense have the rifle checked by a COMPETENT gunsmith to see if the chamber has become enlarged and/or headspace affected. That means someone that knows what they are about...such as Norman Clarke...not a "back bedroom RFD"!
It may also be that the stock had a repaired crack through the hand when it was purchased. Again that would fail and, possibly, create the inertia enough to have the action recoil back from the 'scope. For it is THAT which has happened. The action has gone back not the 'scope forward. With just a normal pressure round.
Is the rifle secondhand? If so you may be able to check the auction house sites here in UK to see if it was obtained through them and catalogued as having a crack through the hand.
I am sorry for the mishap. But at least only your composure was hurt. But I would urge that you MUST get the rifle checked out, as noted above, before firing it again if you do re-stock it.