Update on project....

[raygun]

Originally posted by Hugh
Dave,

Luger barrel threads are M18x1.27 BSF. Hugh

Hugh this measurement is a little intriguing ?

M18 x 1.27 is obviously metric which is what I would have expected .
But BSF is British Standard Fine and is Imperial . Would you care to explain a little more , as I'm interested in such things working in the motorcycle industry where I frequently encounter many different thread forms.