The idea of the Paradox was to incorporate a full choke with the rifling. When shooting shot you end up with effectively an IC pattern.
Polygon rifling- imagine a bore shaped like an octagonal barrel (though it could be 4,5,6 or whatever sided) but the sides in this bore are twisted into a helix just like conventional rifling. I hope that makes sense, but it's one concept where a picture truly is worth a thousand words.
Dearmer-It would be easier to ask who didn't make a Paradox. It was a very popular item and after the Fosberry patent expired most everybody jumped on the band wagon.
In addition to the ones you mentioned, Bland-Vice Versa, Lang-Afrindia, A&N-Jungle Gun, Jeffery-Shikari, Pape-Rhodesia, Tolley-Ubique to name a few.
Pete
