Reed and Columbian vise jaw retaining screws - turning the taper on 5/16 grade 8 screws

Turning a 30 degree included angle on the heads of grade 8 hex socket head screws so that they may be used to replace broken or missing jaw retainer screws on a variety of classic vises from Reed, Columbian and others.
Turning from the backside to the face to avoid engaging the tool in the harder face of the screw all at once. To what degree this matters it also puts the load on the less-worn side of my topslide lead screw.
3 roughing passes around .060" on the diameter per pass; plus a finish pass at .010" diameter at a higher RPM. Removing the burr with a lathe file, then checking with a go/no-go gauge to complete the part.
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