I also found mac's threads are all over the place on my 3 edc's. I cut a 2B major dia almost to the limit and still tight on old (16350) Ti light body sloppy on aluminum, then tried light engine and no go. Sounds like the same issue your having
I'm thinking about building a secondary light engine for my Tri EDC - but need a copper or aluminium pill. Has anyone spotted on in the wild in recent memory? I may have to resort to machining my own if not.
:thinking: Never done those kind of threads before.