I posed the same question over on the "gear" forum but thought I might get more traffic in this MYOG forum.
At any rate, Roger Caffin had the idea in another older thread to cut up an old thermos (vacuum flask) for a light weight stainless bottle. Anyone tried that? If so, what was your experience?
I'm currently using a Klean Kanteen wide-mouth (so my Steripen fits) but it weighs nearly half a pound. I'm aware of the weight savings of plastic but want metal…unlined metal.