Seen two incidents.
One was a P14 chambered for 7.92 Mauser (supposedly a valuable wartime experimental piece) that the owner fired a .308 in by mistake. I was a couple benches oner and got hit by a chunk of the extractor. The owner had some minor facial booboos.
The other was a pre64 M70 .30/06 my son bought where he worked. It had been re-chambered to some .300 mag, but not marked as such. He got some brass bits and powder grains in his face, but was wearing glasses, so nothing serious. That extractor was bent about 90 degrees and the floorplate bent into a shallow "V".
Neither rifle was seriously damaged.
