You are correct; I think kapok was popular, at one time, for insulation in sleeping bags, and I know that kapok was used as a case filler for reloading during earlier days; for I was introduced to its use by the late famous gun writer, Elmer Keith. However, I have not kept up with the negatives/positives of kapok through the years, and, frankly, many years ago, we who do this sort of reloading seemed to have moved toward the dacron filler, because it was so readily available at sewing stores, so I never gave any thought to dacron vs. kapok. Thanks for clearing that up, though it is highly unlikely that I would ever use kapok since it isn't easy to find, or not nearly as easy to find as dacron. I will avoid speaking about kapok from now on, as it relates to handloading (I simply didn't understand the difference until you pointed it out).