I applaud your efforts and don't mean to diminish them but because of the .460 gauge you will experience random failures-to-feed with ammo whose rims are greater than .475" in diameter. .475" is the average rim diameter.I learned by this post I had to remove material from the tensioning wall to reach .460 (closest I could get my homemade gage) . . .
If you get the the chance to make a .465" gauge I recommend you fit the extractor to it. That width gauge will set the extractor to work with a much wider array of ammo (rims from .470" to .480").