m4a1sof , Very Nice! Did you manufacture that red dot mounting plate yourself, or buy it somewhere? I recently picked up a PPQ .22 5 inch model as a .22 compliment to my Q5 match gun. My Q5 has a vortex venom on it but I figured I would have to settle for the iron sights on the .22. I was told the extra weight of the Red dot sight on the slide of the .22 might make the pistol unreliable. Have you found that to be the case?
They don't make one specifically for a PPQ .22, that I could find anyway, so what I had to do was buy an EGW vortex venom mount for a S&W M&P. The dovetail slot is the same size, but to get it to work I had to buy longer screws, and put a shim between the back of the mount and the milled out slot in the PPQ .22 slide. It overhangs the sides of the slide a little but doesn't look too bad. As far as the slide cycling I have had no issues even when using sub sonic ammo.