The .275 Rigby is NOT one of Rigby's namesakes.

There was no such cartridge name as the "".275 Rigby"". The writer like many Ameirican gunwriters just assumes its a real thing because he read some other article that was also wrong. This name is like a virus.

It was always just called the .275. Rigby had nothing to do with the cartridge or its name, other than they chambered rifles and sold ammunition in what was a popular chambering. Even the ammo that Rigby repackaged and sold as ".275 bore" or "".275 High Velocity" was made by German manufacturers, like Geco.

This persistent idea that the .275 is actually called the ".275 Rigby" and that it was a proprietary cartridge of theirs probably comes from people not understanding that Rigby advertised their Mauser rifles as "Rigby-Mausers" and when you bought one chambered in .275, then one might call it a .275 Rigby-Mauser. But the Rigby bit refers to the rifle brand name - not the cartridge!

The first one to ever call the .275 (or the 7x57) a ".275 Rigby" was not John Rigby &Co, they have never done it in any form or catalogue until the recent new company was formed - the first mention of it I can find was by Jack O'Connor in an article in the 1970's, and American writers have followed his lead in this error ever since. British writers in general have not. The usually know it was just called a .275.

If you read the old authors you plainly see that they are aware that a .275 (or sometimes called a .276) is a 7mm Mauser. And you will never see them call it a ".275 Rigby", not will you ever find an original Rigby-Mauser rifle with a cartridge marking of .275 Rigby or any catalogue listing in that name.

Just a big modern misunderstanding. And the notion that the .275 HV was actually a different chambering is balderdash: the HV load was the standard 140 grain load they offered ammo in, and regulated their rifles sights for. (In the UK in those days, the gunmaker sighted the rifle for the ammo you wanted.) The load was more appropriate for deerstalking in Scotland. Rigby didnt even have anything to do with that ammo either, they were reselling repackaged ammo made by other people under their own name - like the rifles themselves.

Please stop promulgating the ".275 Rigby". It sounds likely, but its actually a fantasy cartridge name. But with the internet, it's spreading. The new Rigby company are pretending they invented it and its a real name - (they are young men and probably dont know any better) and now even Hornady are offering brass headstamped .275 Rigby.

It has never existed before - but now it seems to be flourishing. The internet has talked it into existing.