I guess it might be some reference to a cap used in old style rifles where a cap was used to ignite the powder in the barrel and I suppose if it wasn't pressed in tightly … but I really don't know much about that.
Hmmmm, Frank, I don't know about those. A lot of other people have sent us other possibilities for "loosecap" as well, but so far, I don't think we're any closer to solving this one.