Great article Jim. But during the last days of the No1 rifle we had a chart published in EMER's and sanctioned at RSAF whereby some of the Enfield threads could be 'opened out' or 'eased' to a BA size and even 60 degree metric. I seem to recall that 4BA featured too. Have you got a list of these that you could pass on?

On the other hand, originality today might over-rule the old 'utility' criteria that we used to adhere to.

It was this 'thread' thing that made mention using No4 strikers and cocking piece combination in the SMLE No1.