A new introduction will go here shortly.
Experienced gained from Spanish Army service with the Z-45 resulted in Star creating an improved, but still 2nd generation SMG in the late 1950s. This entered service in 1963, as the Z62 in 9 mm Largo. A model for commercial sales only in 9 mm Parabellum is known as the Z63. In Spanish Army service, Z62s largely supplanted Z45s one for one. It was replaced in service in the early 1970s by the mostly similar Z-70/B, below.
The Z-62 is much more compact than the Z-45, largely due to a different layout, where the pistol grip is much closer to the magazine well. The overall tube length, and bolt travel are approximately the same. The buttstock rotates about a point near the pistol grip, so overlaps the rear of the tube as well. An unloaded weapon weighs 2.65kg (5.84 lbs).
The weapon is made entirely of steel, except for plastic grip panels. Many components are machined, with stampings for the stock, tube, trigger assemblies and other exterior components only. The barrel is 20 cm long (7.85") and it can fit 20, 30 or 40-round magazines. Magazines are ejected by pressing a button at the front of the trigger guard from right to left (as on the M-16). The rear sight is a flipover L type within protected wings, with aperatures regulated at 100 and 200 m.
The Z-62 and 62 achieve fire-selection through a somewhat unique two-finger "selecting trigger." Pulling the bottom notch rotates the trigger and fires the gun in fully-automatic mode; pulling the top notch slides the trigger to the rear and fires in semi-automatic mode. Rate of fire in fully-automatic mode is about 550 spm. This is apparently a Spanish Army requirement, as all subsequent Star models have the same rate of fire. The safety is a cross-button in the top, middle of the pistol grip.
These weapons all fire from the open bolt position, but do not have a fixed firing pin. I am unclear as to how exactly this operates.
The Z-70s are basically product improved versions of the Z-62/63 SMG. There are no serious changes to the overall layout or method of construction and the guns are the same size and weight. The 40 round magazine was apparently discontinued for this weapon.
Z-70s are only made in 9 mm Parabellum. This marked Spain's alignment with NATO, and their general move from Largo to Parabellum across the forces. The other major change was to the trigger assembly. The Z-70s have a conventional, single point rotating trigger. Fire selection is achieved via a rotating lever on the left side of the pistol grip, where it may be actuated with the firing thumb. This lever also incorporates a safety setting. The magazine release has been changed to a lever type, below the trigger guard.
A number of other small changes in the overall design were also made. None of these affect general use, and are presumably either to improve performance, longevity or reduce manufacturing costs. These changes seem to indicate that most parts are not interchangable between the two series, despite their optward similarity. I believe that the Z-70 was the commercial and development model, and the Z-70/B incorporated some trivial changes for Army service, but I do not know what the difference between the two weapons is.
For an additional view of the Z70B, see the photo at the top of this page.