Trying to Machine Circles Too Hard

As withj almost everything, CNC is so hard to program that it is faster to drill a pilot hole on the lathe, deepen and enlarge on the drill press, then bore on the lathe.  The LinuxCNC forum has been very helpful, but stuff that works for others doesn't work on mine.  Still wish I could make it work.  5/8" and 3/4" drill bits are pricey.

UPDATE: With some help from the LinuxCNC forum it now works, not as pretty as I would prefer.  Right now it is cutting circles in a hole I made with a 1/2" drill bit.  It may take awhile before it stops looking like a drunk.

What it looks like:
G20 G17 G40 G49 G64 P0.005 G80 G90 G92.1 G94
(cut circle; position at left side of outer circle)
G00 x 0.3195 y 0.5000 Z 0.0000 F 4.0000
(cut circle I radius)
G02 X 0.3195 Y 0.5000 I 0.1805 J0
( clean up debris)
G00 x 0.3195 y 0.5000 Z 0.0000 F 8.0000
G02 X 0.3195 Y 0.5000 I 0.1805 J0
(cut circle; one level in to hog out the center)
G00 x 0.3507 y 0.5000 Z 0.0000 F 4.0000
G02 X 0.3507 Y 0.5000 I 0.1493 J0
( clean up debris)
G00 x 0.3507 y 0.5000 Z 0.0000 F 8.0000
G02 X 0.3507 Y 0.5000 I 0.1493 J0