Actually 17.0::16.4 is a ratio; 17.0/16.4 is fractional. As Skeetx has stated in Liege Belgium proof from 1910-1924 it is simply choke diameter over bore diameter written as a fraction.

Last edited by 2-piper; 11/22/17 11:31 AM. Reason: added omitted words

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