A "1st-era" Glock 17 with the slide locked back displaying its vertical barrel tilt The first-generation (Gen one) Glock pistols are most notably recognized by their smoother "pebble finish" grip and finger groove-much less frames. The Gen 1 frame pattern and structure was employed by Glock from 1982 by 1988 https://gun-sales75318.wikimidpoint.com/3925691/the_kentucky_firearms_diaries