Well I am very glad that my own Swedish Mauser, a Gustav one from about 1903-1905, proved so tough. I was shooting on Bisleys Running Deer Range using some factory 140 grain PMC ammunition when a vastly over pressure round blew the primer pocket with such force it broke the firing pin in half and allowed the rear of it complete with shroud and safety to crash into my glasses denting the metal frame before going over my right shoulder and landing on the concrete firing point.
Apart from the case not wanted to eject form the bolt face due to the firing pin tip being through the flash hole and the rear of the bolt being missing there was no sign of anything untoward
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The rifle was taken to Fultons of Bisley for inspection and checking over and a replacement firing pin fitted. They said it has slightly excessive headspace but then they checked it with a SAAMI guage for some reason and as we know the Swedish specs are different from SAAMI ones. They then fired a few rounds of Norma factory ammunition and it came out perfectly and the rifle has been in use ever since.
After a particularly wet stalking outing with it, yes it's sporterised and is a commercially done job, I needed to strip the rifle and dry it out. It was then that I found that they had not fitted the firing pin nut and firing pin correctly and just forced it on. So much for qualified gunsmiths
so I cleaned up the slots on the firing pin with a Swiss needle file so the nut fits smoothly.
Now what pressures were involved in that factory round I have no idea but the primer pocket was well enlarged and the bolt ejector slot swaged it's imprint on the the cartridge head. I have avoided PMC ammunition ever since.
The experience was a learning one in which I lost faith in the old established firm at Bisley and in PMC something I retain to this day some 10 years later. Since then i had one job done at Fultons and that was to replace the new beech furniture on a No4T and replace it with period walnut and make sure it was bedded correctly. As the Lee Enfield is and always has been one of their speciality fields it was a fairly safe bet
however other jobs I have found other gunsmiths for so they actually lost custom over this.