Pie jaws for rings………what to expect?

So in all my years I have never really used full pie jaws on ring shaped parts…………….I have some 7075 rings(a gear of sorts) 3/8″ thick, 4.75 on the OD and about 3.75″ on the ID…………..right now they are slugged, OD turn, ID roughed and some material is left to add some backbone for the 1st milling OP(keep it from deforming when clamped). On the first mill OP, holes are drilled(they need to be right on for location) then the part is decked. Once the extra material is removed, they go egg shaped due to getting clamped in the vise. They are then removed(now they are round again), and bolted to a fixture for the finish milling the teeth on the ID and two small holes are drilled for location during final assembly. Cuz they are bolted down, all the teeth are all on location as are the locating pins………The teeth need to be “round”(+/-.005) more so than on location with the drill holes…………………

What I want to do is cut a long slug, turn, rough bore and part off mutiple parts in one chucking(less sawing and part handling). Now I have 3/8″x4.75″ODx 3.7″ID blanks. (Obviously clamping in a machine vise will make it egg shaped)………………Pie jaws in some 3 jaw chucks should take care of deformation, no? I now can mill all of my features w/o flippin or fiddlin’ with boltin parts to a fixture. Just clamp in the three jaw and go………………………should work eh? Or what about some really wide soft jaws(2.5″) in the 6″ vises? Encapsulate the whole ring? What’s some of yoos guys’s experiences with similar parts? Maybe I’m just overthinking things?

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