Originally Posted By: ZWhy won't the choke tube of one manufacturer which is the same constriction as the choke tube of another manufacturer pattern the same? They are both the same size and round.
It's not that simple. Sure they are both round and share the same exit diameter, however the skirt design, the length of and design of the parallel section, if the choke strips the wad and if so by what method does the choke retard the wad, there are many factors that distinguish one manufacturers product from another when discussing extended after market chokes. Any and all of that affect individual shot shells construction and influence overall pattern performance. Shotgun barrels and chokes and how they relate to various shot loads are not at all simple and in fact can be quite complex.