I am a "qualified Brno fan" and own a number of them in all configurations. I have hunted with the Model 21s and 22s, the ZG 47 as well as the ZKK series. For a workhorse rifle, the ZKK is hard to beat. One of the early ones with the peep sight in .270 is my go-to rifle. These guns developed a sterling reputation in Africa for their accuracy and dependability. The sights and the barrel band sling swivels endeared them to hunters. I have a 1967 brochure and it shows the peep sight as a standard feature. According to Gary Przibilla in a piece published in Guns & Game, production began in 1964 (I have never seen one this early). Supposedly, production transferred from Zbrojovka Brno to Uhersky Brod between 1964 and 1966 and the later guns were marked "Brno Arms". A 1976 rifle was observed still sporting the pop-up peep sight whereas a 1978 rifle did not. I am not sure how it was phased out. Production evidently ended in the early 90's with ads promoting the rifle running as late as 1995.

The lack of good books and reference works on the wonderful Brno series of firearms makes the pursuit of reliable information difficult.

John