And then there are the ones that weren't fixed properly because the parts no longer were available.
My Enfield 1907 Mark I* upgraded to * * upgraded to * * * Navy rifle is DP on the front receiver ring. So far, I have been shooting it, off and on, since I rebuilt it in 1965 and it still hasn't disassembled ME catastrophically.
If in doubt, one can always do the old pre/postfiring case measurement and, if still in doubt a mild "re-proofing" well could be in order.
You can duplicate the old Proof loads with a max charge for a 174 bullet.... with a 215 seated. Old spare tire and a string are recommended, of course. Made up a sort-of-a-Proof round once for a P-14 which had been sportered and scoped, the holes for the scope base extending down into the chamber (fortunately at the web, so not tremendously hazardous). Plugged the holes with plug-screws jambed together, cleaned up where the bottom one extended slightly into the chamber, made up the Proof round with 1 grain over MAX for a 150, seated a 180 Sierra. pop. Not "BANG!!!", just 'pop'. Still have the rifle today; it makes teeny-tiny little groups all day long.
And that one wasn't even a DP!
Think there could be room around here for careful inspection and reconstruction.