Followup:

I just got a pck of the ten round tubes. These things are tough. I could barely pierce them with an xacto knife, but they cut like pine under the Leatherman's saw. Should be tough enough.

I filled one with water, capped it, and left it cap-down in a bowl about half an hour ago. So far, the only time I got a so much as a drop out of it was after shaking it vigerously at about the 15 minute mark for a minute or so, and it was only a drop.

EDIT: We are now at over 5 hours, and still just that one drop. About three hours ago, I put water into three more, and they have also been sitting int he bowl, heads down. I hearby dub them water tight.

Internal diameter is about .7", and the outter dia is about .8". The caps are 7/8" OD on the dot.

I'm thinking, cut some of these down to about 3", add a small mag firestarter, a smaller SAK or similiar, a water bag, and a folded space blanket to the military surplus 12-rnd shotshell carrier, and it should be decent. <img src="/images/graemlins/smile.gif" alt="" />