[Austin W Hogan]

I am bringing this to the top in support of the call for shell case dimensions that accompanies this post.
Dave, Dean and Larry have measured an unfinished barrel set and found that barrels were initially bored to a full choke contour. Continuing research indicates that the choke contour was often modified, and that forcing cone shape may have been altered to achieve the specified choke.
There are several notes on patterning in The Parker Story, Johnson and Baer. I assimilate them in my mind to conclude that guns were not patterned by counting a 30 inch circle, but by eyeballing a gridded 24 inch square. DuPont bulk smokeless and Tatham No7 shot were used to pattern, unless the customer specified a choice of powder or shot. Many requests were for "as close as can" regarding choke. Guns were often returned to be repatterned and tightened; one must conclude that the original choke taper was modified in this process.
The attached figure shows a magnified contuour of a live bird gun barrel. The plotted points show the difference among several similar barrels that were probable altered to achieve the requested pattern.
Best, Austin