Mark;

Several years back I built a 20 bore double rifle using a pair of the Verney-Carron barrel blanks sourced here in the USA. They were extremely high grade barrels of the finest workmanship of the barrel bore and rifling; and extremely accurate in the final building of the final double bore rifle. At 100 yards the bore rifle would place the right and left shots side by side the same width as the barrel were apart at the muzzle. The barrel blanks I used were rifled the entire bore length, and the rifling was very shallow. Even if VC could not provide a Paradox type rifling at the muzzle, a competent barrel man there in the UK could use the VC full length rifled shotgun and bore/lap them leaving only the rifled portion at the muzzles. The VC barrel blanks were about 1.2 inches in diameter and about 30 inches long.

Steve