The Rogak P18 was a copy of the Steyr GB service pistol, with some disagreement over whether it was unlicensed or just unfortunately made. Les Rogak was a Steyr distributor in Illinois who managed to acquire a set of plans for the GB pistol, and put it into production before Steyr-made examples were available in the US. On paper, the gun seemed quite impressive - a stainless steel 18-shot gas-delayed military pistol in the late 1970s was something on the forefront of handgun development.
Unfortunately, Rogak’s manufacturing left a lot to be desired. Where the authentic Steyr GB was an excellent pistol (despite losing to the Glock in Austrian military trials and to the Beretta in American military trials), the Rogak copy was quite poorly made. The fit on the gas delay system was too loose to actually hold gas pressure, resulting in the Rogak acting as a simple blowback pistol. To compensate for this, Rogak added a sort of fiber buffer stack in the receiver to reduce the slide battering on the frame,