The Barrel drawings in the L C Smith Plans & Specifications show the barrels set to converge at a definite angle. They also give the breech spacing & the muzzle spacing, the pint where the extended axises would cross & the distance apart the extended axises would be at 40 yds. It is "Extremely" easy mathematics to calculate that all dimensions are worked out with "Straight" bores. If a barrel is curved to any extent at all you can "SEE" it with the naked eye from either the inside or outside. I acquired my first double in 1954. In 60 years of looking at double barrel shotguns i have "NEVER" seen one from a JABC up to some much higher grade guns than I have personally owned & have yet to see one with the barrels swamped in like two Bananas back to back. "IF" you have such a gun please do take some good pics of it, take measurements of the barrel diameters at regular intervals & then the width across their outsides at the same intervals & post it all. In other words "Put Up or Shut Up". Double barrels simply are "NOT" assembled in that manner.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra