By todays standards proofing in Germany and the UK follows the same rules.Besides measuring and general inspection the proof loads are 30 % higher than the standard max. pressure of a given cartridge.
Passing the proof succesfully is the whole procedure and not only the result of the pressure test.
Certainly they will put in a pressure load and fire on your behalf . But even if it doesn´t blow up and they have general objections they will not mak it as "proofed".

@Huvius
The pressure test load is still a slim lady in my analogy. The fat man is a case of accidental high pressure(that may exceed proof-loads by far) and following Murphys law , shit happens.

I have to admit that there are many .318 WR rifles around working without fuss and maybe that they withstand the test of the time.

Me too I am playing around with some old mauser rifles having the front receiver ring cut for scope mounting bases (done at least more than 100.000 times on the continent).
But I know about the weakness of the actions so treated.
If someone pointed to that feature I certainly wouldn´t react like a proud mother of an otherwise pretty baby , being told that her baby is cross-eyed.

@ Xausa
Rumor is , even here in Germany that proof houses will principally reject rifles with cut front receiver rings.
Fact is it depends on the depth of the cutting and the cosen cartridge.
A few weeks ago my Ersatzsquarebridge Mauser (formerly 8x57 / now 9,3x57) with cut front receiver ring for the front mounting base succesfully returned from the proof house.
If I had chosen a magnum cartridge (for whatever reason) they would have rejected as I was told.