Like the wz/88 "Tantal, a locally-produced Polish copy of the Russian AK-74S assault rifle, the wz/89 "Onyks" (or "Onyx") is a locally-produced Polish copy of the Russian AKS-74U submarine gun/carbine with a few changes added to differentiate the type from its original. Such weapons are sometimes categorized as "short assault rifles" but are generally considered submachine guns or carbines throughout various western publications. Key differences between the Russian and Polish versions are the inclusion of a three-round burst capability in the latter as well as a side-folding skeletal butt. Additionally, the Polish version features a slightly larger rear sight that can accept the mounting of various sights and accessories as needed. Finally, the muzzle features a compensator that can accept "rifle grenades" for launching from the weapon's barrel.
The wz/ 89 was essentially a carbine form of the longer wz/ 88 assault rifle, the former intended to serve with those battlefield units that could respect its portability - namely security units, vehicle crews, paratroopers and special forces elements. Despite a period of evaluation of an initial preproduction batch (eventually numbering 200 examples), the wz/ 89 was never accepted into service with the Polish Army. Design work was started in 1987 and officially completed in 1990. The project was handled by the Zaklady Metalowe Lucznik firm with manufacture to be conducted out of the Lucznik Arms Factory of Radom, Poland.
Externally, the wz.89 was nearly indistinguishable from its Russian counterpart to the untrained eye. She maintained the same characteristic wood furniture on the forend grip and the long curved magazine. The weapon was of a stout design that fit firmly into a two-handed hold. The protruding front sight post was a noticeable feature of both countries' designs and the low-set barrel was more or less consistent with all previous Kalashnikov designs. The pistol grip was angled ever so slightly and sat behind the trigger which itself was surrounded by an oblong trigger ring. The cocking handle was to be found along the right side of the receiver, just above and ahead of the magazine feed. Spent shell casings are ejected from a port along this right side as well, the port found just above the magazine feed. The folding skeletal butt rounded out the design at the aft end and could be folded over the right side of the gun body. When extended, the butt increased the length of the weapon system to 28.35 inches from its original 20.43 inch length when folded over. The unloaded weight of the weapon was in the vicinity of 6lbs, 6oz and the barrel was of a six-groove, right-hand twist, itself measuring in at 8.15 inches in length. For logistics' sake the Polish version was chambered to fire the 5.45x39mm Soviet cartridge from a 30-round detachable box magazine. Cyclic rate-of-fire was rated at approximately 725 rounds per minute with a muzzle velocity at 3,018 feet per second.
The wz/91 became another form of the Onyks gun family though this version was chambered for the 5.56x45mm NATO standard round. This version was specifically entertained for Poland's possible inclusion into NATO ranks - which eventually occurred in March of 1999 along with the Czech Republic and Hungary.