15.8mm or 15.9mm would convert to a bore dia of .622"-.626" which seem mighty small for a 16ga. A nominal 16ga bore of .662" converts to 16.8mm. Might this number be the muzzle diameter of a tightly choked 16ga? 15.9mm is actually about dead on for 19ga.


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