[GOP_Party_Animal]

but a reverse paradox tube doubles or triples the effective range of these minuscule shotshells. Bloop tubes can extend the sight radius.

Apparently, the author didn't feel the need to clue us in on "reverse paradox" or "bloop" tubes.

[marktwain]

Apparently, the author didn't feel the need to clue us in on "reverse paradox" or "bloop" tubes.

There is a link in the article to an article about reverse paradox tubes.

Bloop tubes are more common. As stated, they extend the length of the barrel so as to extend the sight radius. Not all need a threaded barrel.