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???

[ithacaartist]

postino,

I found this at http://metricationmatters.com/mm-new...r-2011-03.html

Soft conversion takes the old pre-metric measuring word and converts it into its nearest metric equivalent by using a metric conversion factor. As an example, suppose that you wanted to convert a one-inch bolt to its metric equivalent. This is not as simple as it sounds because throughout history there have been many different inches. These have been different in their actual length as well as different by definition. You will possibly need to know the history of the bolt you want to convert and the history of the machine it came from.

Among the most recent inches were the British inch, the Cape inch (South African), the Enfield inch, the USA inch, and the Canadian inch that subsequently became the international metric inch (exactly 25.4 millimetres) that most people use these days. If the one inch bolt was from the UK, I think that the inch you are referring to is the Imperial inch. However, if the bolt you are referring to was used for the design and manufacture of British weapons it is possibly the Enfield inch &ndash – an Enfield inch was a little smaller than a British inch at that time; it was about 0.9997 British inches. As an example of the use of the Enfield inch consider the Enfield 303 rifle; its bore was measured as the decimal fraction, 0.303, of an Enfield inch.

And the British Militaria Forum is goin' at it, too http://britishmilitariaforums.yuku.c...s#.T4x6gtnp6QA , in part dealing with the Whitworth threads, no stranger to discussion here. This helps explain why.

Fun.

DP