It has been observed that on most P22's the trigger bar ears are rough and will eat into the zinc slide. To combat this you can disassemble the gun, and sand down/smooth over the front edges of the trigger bar ears and this should fix the problem. I did it with mine and while I didn't quite do it enough, it did almost entirely fix the problem.tace said:
For information on completely disassembling the P22 and doing this sort of work take a look over at the rimfire central forums where under the Walther section one of the "stickies" has to do with the "P22 Bible" which is a big long PDF detailing all of this.
Hope this helps.
C