youll certainly get a small bit more consistency in the bullet size vs using as cast diam. and thats never a bad idea.
as an example ,in my 458 win, Remington bolt action, Id tested as cast .460 diameter bullets lubed vs ..459 sized and lubed 405 grain bullets

over 55 grains of IMR 3031, I got no measurable difference in 100 yard bench rest accuracy, everything shot into about a consistent 2" 3 shot group.
my friends ruger #1 had the same results, he used that ammo for local hog and deer hunts with good results