For those readers that do not know, the 308 family has a case head size of .473" and the PPC has a head size of .445". The 308 extractor is not designed to reach in that far to grab the lip of the brass. The bolt head is larger than the case head by design, in the Savage bolt heads, its around .493". If the extractor is tuned well, it will work perfectly with the PPC and there is no need to get a custom PPC head made just for that. If you buy a customed head from SSS, it will have the lugs and face trued, radius removed for the washer reposition and a tuned ejector installed. You can also get a PPC extractor that is slightly modified to reach out a little further when used on a .473 head. The 223 head's extractor hole is closer to center and the PPC extractor is not needed. I do not know what extractor SSS offers with their PPC head but I would guess the unmodified steel version. Either way, I think SSS has switched to the .140" balls.
The .140" ball centers in the hole better and therefore holds the extractor in a more centered position. With the factory .125" ball, you can push the extractor back and forth about .020" and it will stay. Use a bigger ball and much of that slop is gone and inconsistant ejection with it.
SSS will fix you up.
Cheers,
Rob