Finishing a hole in cast iron - boring vs milling ?

[dansawyer]

The project is to round out a hole in cast iron that has been worn out of round. The original hole was an alignment, bearing, surface for the feed shaft, 3/4 inch diameter, on a lathe. The lathe takeoff 'shoe' is totally held in place by the feed shaft. Over time the feed shaft wore the hole 'oblong' in shape. It is still close to 3/4 inch in one dimension, but .92 inch in the other. The project is to bore the hole back into circular shape and light press a bearing in the new hole with the original 3/4 ID of the original hole.
Assuming using a cnc mill to machine the hole and assuming the part is properly mounted and aligned in the mill - what is the best machining process - milling or boring?
My inclination would be to use an end mill and take 25 thousands or so cuts, both deep and wide, in a circular pattern. Is there an advantage to boriing that I am missing?

 

[benmychree]

How deep is the hole?

 

[dansawyer]

Sorry, my oversight. It is in 2 parts. Each part is about 1/2 inch thick; these are the bearing surfaces. The parts are separated by about 3 inches where the shafts go. The total is about 4 inches.

 

[Mitch Alsup]

Boring has the advantage of allowing the final hole diameter to be of any size.
Milling has the advantage of being fast.

If you are making the press in bearing, you can choose either to get the job done.

 

[benmychree]

Doing it with an mill seems problematic in light of the distance between holes and resultant alignment issues from one end to the other, If I was doing it, I'd make a line boring bar and use a bearing at the far end of it. Since exact size is not an issue, a tool set by hand is not a problem.