A couple of thoughts.... The original extractor is only .007 thick in the area where the rim sets, this is why they crack and later break off. In discussing a \"unsupported chamber\" and the pros/cons, I don\'t think the .007 wall provides a hell of a lot of support, thus the cracking and later breaking off. The new spring is a spring so it does not provide any support itself. I suspect in the drawing above, the original extractor hook with a section cut out for the new finger would be even weaker and break off quickly under use.
I know it would be a PITA but the \"proper\" way to implement a extractor as drawn would be to get rid of the original DE extractor hook (if its not broke off already LOL) and just go with the new extractor. Unfortunately, the barrell ring would have to be redone and the groove in the barrells to restore chamber support, possibly another method .
My plan, which is more involved, is to make extractors as drawn above, just like nearly every gun commercial made uses. I used ruger 10-22 barrels on my gun, which are chambered for long rifles of course, so I can put the barrells back in the lathe and square off the end to remove the existing cutout for the original DE extractor hook, chamber will still long enough for 22 shorts. The finished barrels would be maybe 50 thou shorter but who is going to notice that? THEN... I plan on remaking the barrell ring and going to a wedge clamp arrangemet for holding the barrells that was detailed in another thread on here.
I know its more work, but the finished product would have a fully supported chamber, good extractors, interchangeable/removable barrels and............... WORK..... the most important thing LOL
The extractor drawn above is the best solution. It is what nearly every gun manufacturer uses, because it works well. The RG gun uses this method and does not have extraction issues. If done in a initial build I think its even easier than cutting the DE extractor hook.