Thanks folks! I kind of figured that it was truely a "hit or miss" proposition, but trimming that barrel back a bit made me delve into the lore of chokes more deeply than normal. Lots of people have very-closely held convictions on the subject (at least in what they write). I figure that if I've made a complete hash of it, I can always cut another half-inch off and go with choke tubes. The true test will be the patterning board or the dove-opener, whichever comes first.