well only YOU can answer the question "should i return it for repair"
if you are content with the function of the weapon then its good to go, if not then you need to do something, and certainly returning it for repair/service is a viable option.
personally every weapon that i own functions 100% (including my 22 plinker pistols) but hey thats me.
I no longer own a 709 but did and must say my particualr pistol was 120% reliable on every round that i ever put in it, including some 8-10 different manufactures and 5-6 different projectile types including hollow points.
there were things that i did Not like about the 709 but reliability ceratinly wasn't one of them.
rails, slides, barrels wearing is simply a part of an automatic seating itself together, every auto that i have has some matching wear somewhere on it.
BY the way welcome to the forum.