Similar to the Soviet AK-74 the Polish Tantal rifle is gas-operated. The receiver is stamped steel and houses an newly designed trigger mechanism. The selector switch has been moved to the left side of the receiver and has three positions. The large lever on the right side acts as the safety lever only.
The Tantal is a selective fire, gas piston operated weapon that taps expanding exhaust gases off through a port in the barrel to a gas cylinder above the barrel. The barrel is locked against its longitudinal axis by a right rotating bolt. A spring extractor is contained inside the bolt head, and a fixed ejector—inside the receiver housing.
The fire control selector, with its lever located on the left side of the receiver wall, enables fully automatic fire (lever in the “C”-marked position), semi-automatic fire (“P”) and 3-round burst fire mode (“S”). The selector can be operated with the safety either engaged or disabled.
The weapon is secured against misfires through a manually operated safety (whose lever, as in the AKM is located on the right side of the receiver), that disables the trigger bar and limits the movement of the bolt carrier. Sliding the safety selector to the top position (marked with a “Z” symbol) secures the weapon, lowering the lever down (“O” setting) disables the safety. The Tantal feeds from a double-column curved box magazine, made from a synthetic bakelite material or stamped metal, with a 30-round cartridge capacity.
The cold hammer forged barrel has 4 right-hand grooves at a 200 mm twist rate. It is equipped with a multifunction muzzle brake that can be used to launch rifle grenades.
The Tantal features a metal wire side-folding stock (folds to the right side), ended with a profiled shoulder pad. The rifle can also use a fixed wooden or synthetic buttstock designed for AKM or AK-74 rifles. Both the upper and lower handguard and pistol grip are fabricated from bakelite, although a limited number of Tantal-specific black polymer handguards and pistol grips have also been produced. Most handguards designed for use with the wz. 1996 Beryl assault rifle may also be installed on the Tantal.
The rifle has mechanically adjustable iron sights that consist of a notch on a sliding tangent and forward post. The rear sight’s drop arm has a range scale engraved with settings from 1 to 10 (corresponding to firing ranges from 100 to 1,000 m, graduated every 100 m) and a fixed setting “S” that is the equivalent to setting “4” on the range scale. Additionally, the sight assembly is fitted with a radium gas illuminated vial that enables use in low light and near dark conditions.
The wz. 88 rifle fires the intermediate 5.45x39mm round with either standard, tracer or training cartridges, all produced locally by Zakłady Metalowe "Mesko" in the town of Skarżysko-Kamienna.