Any of you GT'ers know what year Glock began roll-marking the slides on the Forties "40" - from the previously marked "40S&W?" I have seen both the G22, and G27 with these markings in Sweeney's book. Also not sure if the G23 was similarly marked, as I have not seen a photo of one. Any answers on this would be appreciated. Already checked the Archives - if I missed that post, please let me know. Thanks Wanna kill these ads? We can help!