I have a slide mounted RTS2 on a CZ P09. With the new 140mm mag rule I am running 23rds. I have had zero reliability issues with the slide mounted optic. I am also running a reduced power recoil spring. Several shooters in my area are running M&Ps, Glocks, & Sigs with optics from Leupold, Trijicon, and Burris. The only reliability issues are ammo related. Sent from my iPad using Tapatalk