Here is something I've always wondered about as I watch the evolution of the Glock family. The 17/19/20/21 slides are squared off. By way of contrast the 26/27/29/30/37/38/39 models have nice sculpted corners at the barrel end of the slide. Why didn't Glock do that for all their models? If they can make the recoil properties work for some why not all? Wanna kill these ads? We can help!