Ive seen those extractor cuts filled with a t-slot looking blank that fits tight and blended in with a mini m16 installed. Ive also seen those extractors modified to slide farther by changing the ball detent underneath or a new longer one from kelblys fit to match. Ive seen the spring and plunger hole filled and redrilled to bring the plate closer to the case. The way alan did things though is that was a ppc action modified to take a br case initially. Ive seen a bunch over the years that still had the original extractor in there with the boltface opened up so im betting itll pull a ppc right now. Bushing the OD would be simple and icing on the cake.