I am boring out some deep c-bores in 303. I am taking 3 .005 finish passes and using a helix plunge. When I look at my helix the edge in between my next to last and last finish pass, meaning the helix is leaving .0025 on the wall so if I get a little tool flex (.25 flat end mill) it will leave a line in my bore. I am pilot drilling the bore before so is there a way to change where the helix plunges? using pocket not contour.