There's no such cartridge as the ".275 Rigby". It wasn't a proprietary cartridge that Rigby "owned" in anyway.
It was just the .275, (which everyone knew was the 7mm Mauser.) The same way the 6.5 was called a .256.
They never sold ammo headstamped ".275 Rigby"" and the their brand of ammunition had on the box: ".275 bore - Rigby Special High Velocity""
When someone said they had a .275 Rigby Mauser, they meant the cartridge was a .275 and the rifle was a Rigby Mauser. Not that they had a "".275 Rigby"" in a Mauser rifle. No one for example, ever bought a rifle from Thomas Bland or Gibbs chambered in 7mm Mauser and called it a "".275 Rigby"" It was not like the .223 REmington, or the .308 Winchester.
But after twenty years of misunderstandings on the internet people now call the cartridge a .275 Rigby. Even Craig Boddington does it. They think that it was a propriatary Rigby cartridge, or it was "renamed by them"", or ""that was what it was known as in the UK"". It is now so universal that people are getting their custom rifles stamped with "".275 Rigby"" and - the new Rigby company are actually now selling ammo marked .275 Rigby! So the internet has created something original thinking it is traditional.
The internet is a fascinating place.
Then how do you explain that decades before Al Gore claimed to have invented the internet, my John Rigby and Sons Mauser rifle was was inscribed by the manufacturer as .275 Rigby as the chambering?
