I bought a bunch of 1.347" cones for a couple of Form 1 cans.  Original plan was Apogee Products #002 tube (really cheap....), but realized after the first one that steel tubes are FREAKING HEAVY.

I'd rather not have to re-buy cones to make a Ti tube work when I've got a bunch on the workbench, but all the Ti tubes I can find have a 1.355" or bigger ID, and that seems like too much slop for concentricity's sake.  I can always shim/tape the cones to fit, but then I'm not getting them out, ever, after the first couple of shots.

Any ideas?

8 thou is not a big deal. The most your parallel alignment could be off is 4 thou. If a baffle strike is imminent, this clearance dimension has nothing to do with it.

Check out DM's ASR tube.