My lack of knowledge in english didn't make the link beetween rifle and groove... And I do not have a passion for weapons either.
But that specific technical aspect did get my attention. And the D'Artagnan trivia was linked thanks to a lecture I was attenting to for work.
But yes, that detail greatly improves precision and distance a bit thanks to a better aero position of the bullet on the trajectory, for same mass/size of bullet/powder. I guess the need for better manufacturing probably also had a role for distance.