I had many hours of shooting the gun at the range.Never any signs of any thing wrong.Then that first round out of the new box of factory rounds.Smoke come back around the bolt.Had to take a rubber hammer to open it up.Primer gone.Parts of the bolt face gone.Had the chamber cast.Chamber was out of round.Sent the rest of the box back to the factory.Have not heard anything yet.
If you are having lug set back in the receiver, due to soft receiver surfaces, then the action is only useful as a tomato stake.
The 98 Mauser goes all the way back to 1898. Metallurgy was awfully primitive and inconsistent back then.
So while the 98 is an outstanding design, you could have one of the M1909 Argentine, or Brazilian actions that look great but are made of plain carbon steels that were never high quality to begin with.
By the time you get to the 50's, metals processes are vastly better. Modern alloy steels are even better, much higher yeild strengths.
You never said just what vintage your Mauser. Interarm Mark X mauser actions were chambered in 300 Win Mag and if your Mauser is one of those, it should hold.
But a chamber out of round? If pressures were so high as to deform the chamber, and you are not hurt, then I think your Mauser did pretty good in protecting you.