[1] : The Collaborative International Dictionary of English v.0.48

rifling \ri"fling\, n.
   a the act or process of making the grooves in a rifled
       cannon or gun barrel.
   b the system of grooves in a rifled gun barrel or cannon.
       1913 webster

   shunt rifling, rifling for cannon, in which one side of the
      groove is made deeper than the other, to facilitate
      loading with shot having projections which enter by the
      deeper part of the grooves.
      1913 webster
see also:
shunt rifling 

Shunt >> S Words
Shunt, definition of term: Shunt
shunt_pag1.html

Rifling >> R Words
Rifling, definition of term: Rifling
rifling_pag1.html