In Mallet 1, I was able to get a VP9 to release its striker with a hit on the bottom of the grip.
Today I spent some time looking at the internals of a PPQ, a pistol I really, really like, with arguably the best trigger in the SFA world. I had previously been a little smug because there is no way a PPQ can release its striker when hit on the bottom of the grip. However inspection and a little thought showed me that it may have a weakness when hit on the back of the slide.
Mr Mallet came out and in this video I demonstrate a Walther PPQ M1 releasing its striker with a mallet hit to the rear of the slide and with a drop of 18" landing the rear of the slide. I also made this happen with a Walther P99 AS trigger and imagine it would work the same in a PPQ M2 or any PPQ variant.
I apologize for any incorrect terminology in demonstrating the pistol's internal parts.
To make it clear, the pistol would not discharge unless the striker channel block simultaneously malfunctioned.
The VP9 required a much harder hit than the PPQ to release FWIW.
It makes me a little sad, as it rules out, at least for me the PPQ as a carry pistol. The P99 AS I tested decocker and was able to fire in double action mode after the hit or drop.