I found the piece of stainless tube in a pump I was stripping for parts, as a CR123 slid straight in it was an obvious starting point. All the end caps are press fitted.
The module I made up as I went along, I still think it is my best laser build to date.
Thankyou kind sir.....
I wish I could make more of this style but like thejunkmonger I have mainly built from what is lying around the workshop, in this case:-
stainless steel tube pump ram for the barrel
A stainless steel cap from a pressure cell (much modified)
and the bit that I like best the thread that holds it together is a double helix thread from the lens of a camera I scrapped to get the dichro from the rangefinder.