I was there this week and had a salesperson telling me that the glock 34 without any ports in the barrel was compensated to reduce recoil. That's why the slide was missing the top: to allow gasses to escape. I looked at him as if to see if he was kidding. I checked the barrel for ports, none. "It's compensated, alright, and does a great jib of reducing recoil because the gasses escape through the top of the barrel." Ok. Magic compensation through the top of a barbell without holes. Sigh