I thought all of those issues were corrected with the recall for M1 and corrected with the M2 design.I'm pretty sure I have not read of a cartridge being ignited due to a short stroke. The fact is that if the striker is not caught by the sear, it will follow the slide forward and the nose of the striker will rest on the primer. Early on there were a couple of Members here who removed the projectile and powder from a few brands of ammo and repeatedly, purposefully dropped the slide/striker onto the live primer. In each case a small indentation was made in the primer although none were ignited. A very brief and narrow test done here only... It should be noted that in many other striker fired pistols the firing pin block is located near the rear of the chamber....on the CCP, it is almost all the way to the rear of the striker's travel and near the sear, and, is what allows this situation to occur. Any semi auto can short stroke. I don't know of any others that allow the striker to contact the primer should this occur.
It is a bit unnerving to many that this can occur, in fact it is possible to chamber a round from the mag while purposefully short stroking....in that case there nothing to stop the striker from moving all the way forward. I discussed this with the Chief engineer in Germany and this had been thoroughly tested prior to the release of the pistol. One of the answers I'm not in agreement with. The other I think is correct. Forward movement of the slide during a short stroke does not allow the light weight striker to generate enough speed to ignite the primer.....perhaps not....but this is an issue some of us are not happy about. It is a poor design no matter what spin you put on it in my opinion and I don't know why Walther designed it this way. If you look at other Walther striker fired pistols you will see the firing pin block sits forward, near the chamber and is in position to catch the striker as soon as it moves a quarter of an inch or so rearward of the chamber/cartridge....
Obviously if you pull the striker rearward and were to release it...in some manner, say by pulling the trigger, the speed and mass of the striker will ignite a cartridge. I think if it were not for the forward movement of the slide slowing the non captured striker down....it would ignite a round.
The other test that I've seen a video of is a drop test. UTube, so I can't attest to it being 100% accurate....in other words it was not done at a factory test facility. But, the testers allow the non captured striker to rest on a live primer. They then do a drop test, muzzle up, and the primer fires. The theory here is that the impact drives the primer into the nose of the protruding firing pin. My theory is that the impact drives the striker rearward, compressing the striker spring and as it rebounds....there is no slide to slow it down and it hits the primer hard enough to ignite it. So, if the test is accurate for whatever reason...the location of the drop safety is too far rearward to be effective on a non captured striker making the pistol unsafe if dropped.
All of this is nothing new and has been a concern discussed from day one. But I don't remember ever reading of a short stroke igniting a round. It is still a less than desirable situation as far as I'm concerned. I hope that explains the concern many have discussed. 1917