Do not mean to hijack the thread. I fired a friends replica Whitworth several years ago. That got me into the Whitworth research mode.Whitworth was the very first gunmaker to build rifles toto very close tolerances. It was nearly impossible to reloadthe oldCivil War rifles after firing. They came with a steel ramrod and it was normal to bang the ramrod on a stump or tree to reload.

Whitworth was the father of close measurement. Prior to Whitworth it was nearly impossible to get a bore within.010of spec. Whitworthdeveloped systems tomeasure as close as one-millionth of an inch. He standardized machine threads. The system is called Whitworth.

Whitworth re-worked existing machine tools to much closer tolerances than previously thought possible.