Cantom has got it right, the stronger spring is half the battle. also makeing a new ejector screw, which is cut back as little as possible, helps lots to. the screw that holds the safe lever on is the same thread, and can be used to make a new longer ejector screw, if you can find a spare.
i start by cutting/ filieing / stoneing just under the " hook" of the extractor.
you can file lots off, and it will eject great, but , if you notice in the pics, the 7.62 extractor has a much longer nose on it. this is to help start the extractor into the milled slot in the bbl upon closeing.
i found out the hard way, that if you take to much off the underside, the extractor will not go into its milled slot in the bbl. it will nose into the breechface of the bbl.
go slow, and test often, it doesnt take much to make it work much better, with the longer extractor screw.
hope you dont mind MARITIMER, i stole your pic
you can see where i drew the white line, this is how i start. you can see how it will let the nose or tip of the extractor fall closser to the bore, and how it will nose into the breech face, if you go to far.