Jim;
The drawings from the Smith Plans & specs book seem to indicate the bbls remained straight & were set to the convergence I mentioned in the previous post. I didn't get the book back out for exactitude, but the figures I cited are extremely close. They in fact gave the point of convergence of the bore axis a few feet from the muzzles & the seperation of the axis at the 40 yd range. It may not have been the exact 15" I gave but was within a half inch of that.
Upon acquiring this book many years ago & seeing these figures I did a rather informal check on some of the Lefevers I owned at the time. The first check of muzzle vs breech spacings revealed they were about the same as those given for the Smiths. Then working from the outsides using a good set of Starrett dial calipers I measured the bbls OD's at regular intervals & then at the same places measued the total widths across the two bbls. Going this method one of course is simply assuming bore to OD concentricity but plotting the centerlines of the bores revealed essentially a straight line & on several differnt guns of varying weights they all plotted very close to that .011" per inch convergence of the Smith drawings.
In measuring a good number of bbl OD's on various doubles over the years I have found the vast majority of them are slightly "Beefed Up" in the choke area,IE the dia runs larger over & slightly ahead of the chokes than from behind the chokes back to about the mid point of the bbls.
If the bbls were squeezed in anywhere near to paralell for much length behind the muzzles this would be readily apparent just looking down their OD's. In all the guns I have owned or handled much over the years I don't recall ever seeing this condition, "BUT" I certainly am not saying it has never been done, just that I have never personally noted it.
While admitting I am not real experienced at reading the internal shadow rings, on those on which I have tried I have never observed what I took to be a distinct & intentional curve. My observations have been the bbls as set in are as straight as build tolerances allowed & then set to that converging angle, which is incidently about 0°38' included, trigging from the .011" per inch of convergence.
