Mike, I dont' believe the P22 has ever had a problem with extraction that was a pistol problem....dirty chamber, yes. The problem was with ejection direction. The pistol would throw hot brass every direction including right between your eyes. There is too much to list here on extractor work I did in experimenting with these pistols but the first step was to peen the original extractor so as to reduce the gap between the extractor tip and the breech face. Note: do not attempt this with the new extractors, they will break. I determined that the problem was due to the extractor not holding the rim close to the breech face.Okay, I am willing to be educated: what is it, precisely, about the current magazine that cures a last-round failure to eject? Higher protrusion of the follower?
(I should have dragged my early P22 out of the safe for a refresher view before getting involved in this thread. I take your point that the breech face is not configured--there's practically no left buttress-- to allow the extractor to positively hold the fired case in position to be ejected, so the extractor is unlikely to be the culprit.)
When firing a blowback operated .22 such as the P22, blowback gasses forcefully blow the spent case out of the chamber. The extractor plays no part, in fact the extractor isn't even necessary. Take yours off and fire it. It will extract fine and eject pretty good too. Not good enough, but pretty good. The extractor is used for manually unloading the pistol. Now having said that, I did find that the extractor should play an important part in ejection direction. What if did was either peen the original extractor tip rearward to reduce the gap and I filed a new extractor out of my barrel nut wrench where I made the gap so precise that the extractor would hold a rim pressed against the breech face. But while this was of no benefit in extracting a fired case.....it was extremely important regarding ejection direction. With a tight extractor, ejection direction was forceful and in a consistent direction. What happens is that when the left side of the rim hits the ejector, a tight extractor catches the right side of the rim and causes the case to pivot over the extractor. So in this situation the extractor plays a "pivotal" role you might say.
I discussed this at length with the engineer responsible for the P22 and other Walther small arms and he agrees but due to the world wide variety of rim thicknesses.....Walther can not install my tight fitting concept. They did however revise the extractor to reduce the gap and that did improve the situation.
I sent all the stuff to VQ and asked if they were interested and they were. Their extractor is more precisely made than the Walther one but still did not close the gap all the way. I'll put up a link to the history on all of this. So, extraction has never been a problem, ejection direction has. One final comment.....the 10th spent case usually does not eject like the previous ones due to the follower not matching a real round. So, I modified the follower on one B mag so that when the mag was empty the follower would sit exactly like when a round was in the magazine. That cured the last case flopping out of the pistol when firing and restored it to forceful ejection. M1911