Caliber: 5.56x45mm NATO (SS109/m855)
Lenght: 998m
Barrel lenght: 450mm
Weight,empty: 4.07kg
Magazine Capacity: 30 rounds
Rate of fire: 670 rounds per minute
Effective range: 500 meters

The AR-70/223 and AR-70/90 rifles are very similar in basic design, but with some differences. The description below is for AR-70/90, with differences to 70/223 noted, where appropriate.

The AR-70/90 is a gas operated, magazine fed, selective fire weapon. The receiver is made from stamped sheet steel, and consist of two halves, upper and lover, connected by two cross-pins, at the rear and at the front. For maintenance and field stripping the rear pin is pushed out and the receiver is hinged around the front pin. If required, the front pin can be removed too, so the receiver halves will be separated completely. On the AR-70/223 the upper receiver is of square cross-section, with stamped bolt guides. This design proved to be not strong enough, so the AR-70/90 features a trapezoid-shaped upper receiver cross-section, with separate bolt guides welded in place.

The gas operated action of the AR-70/90 is fairy conventional, with the longstroke gas piston, located above the barrel. The gas piston rod is linked to the bolt carrier by using a cocking handle as a lock, and the return spring is located around the gas piston, above the barrel. The gas block featured a two positions gas regulator (for normal and adverse conditions), and the gas cutoff,integral with raising grenade sight. When grenade sight is raised into the firing position, it automatically closes the gas port. The rotating bolt is somewhat similar to one, found in the Kalashnikov AK-47 rifles, and has two massive lugs, which are locked into the barrel sleeve, which is welded into the receiver. The charging handle is attached to the bolt carrier.