The "Enfield Inch"...???...

[sheepherder]

I'm in a discussion on a Commonwealth forum for Lee-Enfield rifles, they are commenting on how the Enfield caliber is measured across the lands (.303 cal for example) while her in the US we measure across the grooves (.308 cal for example)...

Then someone mentions "The Enfield Inch", which is not quite an inch...There is actually .0003" difference...

...But no one will commit to whether it is .0003" larger than a "standard" inch, or .0003" smaller...

Here's a link to what you would think is the definitive explanation...The Royal Small Arms Factory Apprentices Association web site...But even they don't say!!!

http://www.rsaf-aa.co.uk/rsaf/heritage/enfieldinch.html

So...Are there any of our British friends here who can say exactly what "The Enfield Inch" is???