What's the advantage of Ruger Mark III's fluted barrel?

[G.T.]

My dad owned a sporting goods shop in the 50's and 60's, and it was my childhood stomping grounds... (fond memories)
I once asked him what was the main difference between a 28" and a 30" shotgun barrel? He smiled slightly and said, "It puts you two inches closer to the goose!"... ... Those were simpler times! I miss them! Best to all, til...lat'r...GT....