I think that "regulate" is an English term that was once used by gunmakers in relation to setting up sights for a particular round in any rifle or gun. The modern usages of 'sighting in' or 'zeroing' come from the more vibrant 20th century US shooting literature.

Only in doubles has the English usage survived because the English culture has so much significance in that sphere, and a separate term was needed to encompass the physical correction of the two barrels.