Image credit
- Title
- File:Museo Eibar Subfusil Z-84 STAR.JPG
- Author
- Txo(attribution required)
- Licence
- CC BY-SA 4.0
- Source
- https://commons.wikimedia.org/wiki/File:Museo_Eibar_Subfusil_Z-84_STAR.JPG
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- v359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 270 mm. Velocity outside the sourced range is not projected.
1 of 2 inputs link to their source.
How Muzzle velocity is calculated
nearest sourced barrel length, no extrapolation
Inputs
- v at 101.6 mm359.7 m/s1,180 fpsverifiedsource1180 fps as published.
Assumptions
- This figure belongs to a 101.6 mm barrel. It is shown because it is the closest measurement that exists, not because it applies here.
1 of 1 inputs link to their source.
How Loaded mass is calculated
m_loaded = m_empty + m_magazine + n · m_cartridge
Not calculated: m_magazine has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- One magazine, filled to the stated capacity. Spare magazines, optics, slings and lights are the owner’s, not the arm’s.
2 of 4 inputs link to their source.
How Free recoil is calculated
E_recoil = ½ · m_firearm · v_recoil²
Inputs
- m_firearm3.15 kg6.945 lbestimatedsourceLargo/standard barrel, from the infobox; no inline citation is given there.
- v_recoil0.8509 m/s2.792 fpsestimated
Assumptions
- Propellant gas momentum is excluded: ARMAG does not record charge weights. This is therefore a lower bound on the real free recoil, consistent between entries but smaller than a figure that includes the gas term.
- Free recoil: the arm is unrestrained. Stock design, muzzle devices, stance and shooter mass are not modelled, because none of them is a property of the arm.
1 of 2 inputs link to their source.
How Capacity is calculated
as published for the primary chambering
Inputs
- capacity30estimatedsourcePublished as a 25- or 30-round detachable box magazine, from the infobox, uncited there; 30 rounds recorded here as the larger of the two published capacities.
1 of 1 inputs link to their source.
Derived figures
Computed from the sourced values above. Open ƒ on any figure for the formula, its inputs, and the assumptions it makes.
How Momentum is calculated
p = m · v
Inputs
- m7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- v359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 270 mm. Velocity outside the sourced range is not projected.
1 of 2 inputs link to their source.
How Sectional density is calculated
SD = mass(gr) / (7000 · diameter(in)²)
Inputs
- mass7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- diameter9.03 mm0.3555 inverifiedsourceCartridge maximum, dimension G1.
Assumptions
- Reported in the conventional lb/in² so it is directly comparable with published figures.
2 of 2 inputs link to their source.
How Power factor is calculated
PF = mass(gr) · velocity(fps) / 1000
Inputs
- mass7.452 g115.0 grverifiedsource115 gr as published, converted to grams.
- velocity359.7 m/s1,180 fpsverifiedMeasured with a 101.6 mm barrel, not this arm's 270 mm. Velocity outside the sourced range is not projected.
Assumptions
- A competition classification defined by the IPSC and USPSA rulebooks, stated in their units. It describes a scoring category, not an effect.
1 of 2 inputs link to their source.
How Magazine dump is calculated
t = (n − 1) / (rpm / 60)
Inputs
- n30estimatedsourcePublished as a 25- or 30-round detachable box magazine, from the infobox, uncited there; 30 rounds recorded here as the larger of the two published capacities.
- rpm600 rpmestimatedsourceFrom the infobox, uncited there.
Assumptions
- Cyclic rate held for the whole magazine, no stoppages, trigger held down. A theoretical figure for comparing mechanisms, not a measured one.
2 of 2 inputs link to their source.
How Sight error at 1 mm is calculated
θ = atan(misalignment / sight radius)
Not calculated: sight radius has no sourced figure yet. Nothing is substituted for a missing input.
Assumptions
- Shows what a stated aiming error costs. The misalignment is the reader’s figure; the site does not claim how well anyone aims.
No input on this calculation carries a clickable source yet.
Variants
Corto
The short-barreled version of the Z-84, with a shorter barrel and correspondingly shorter overall length than the standard Largo.
- Mass, empty
From the infobox, uncited there.
- Length
Stock extended, from the infobox, uncited there.
- Length, folded
Stock retracted, from the infobox, uncited there.
- Barrel length
From the infobox, uncited there.
| Variant | Years | Changes |
|---|---|---|
| Corto | — | Mass, empty, Length, Length, folded, Barrel length |
Specifications
Every row here is generated from the schema, so a figure recorded on this entry cannot be missing from the table, and the same rows, read the same way, are what the comparison shows.
Identity
- Type
- Submachine gun
- Action
- Self-loading
- Fire modes
- Semi-automatic
- Fully automatic
- Operating system
- Blowback, simple
- Designed in
- Spain
- Produced in
- Introduced
- 1984
- Production
- not recorded
Dimensions and mass
- Mass, empty
Largo/standard barrel, from the infobox; no inline citation is given there.
- Magazine, empty
- not recorded
- Length
Largo/standard barrel, stock extended, from the infobox, uncited there.
- Length, folded
Largo/standard barrel, stock retracted, from the infobox, uncited there.
- Width
- not recorded
- Height
- not recorded
- Barrel length
Largo/standard barrel, from the infobox, uncited there.
Sights and rifling
- Sight radius
- not recorded
- Sight height over bore
- not recorded
- Rifling twist
- not recorded
- Twist direction
- not recorded
- Grooves
- not recorded
- Sight graduation
- not recorded
Operation
- Cyclic rate
From the infobox, uncited there.
- Trigger pull
- not recorded
- Effective range
- not recorded
- Units produced
- not recorded
- Launch price
- not recorded
Chamberings
- 9x19mm Parabellumprimary30 rounds
Scale
A to-scale outline against family siblings. The dimensions are sourced; the shape is a representative outline for the type, and says so.
- Star Model Z84670 mm26.38 inheight not recorded
Representative outline: the dimensions are sourced, the shape is not. Overall length, and barrel length where recorded, are drawn from this entry's own figures; the profile is a generic one for the firearm type and says nothing about this arm's actual contours. Star Model Z84 records no height, so its outline is drawn at the type's proportion. That height is part of the shape, not a measurement.
Detail
The Star Z-84 is a simple-blowback, open-bolt submachine gun Eduardo Iraegui designed in 1984, using a telescoping bolt that wraps around the rear of the barrel to keep the weapon’s overall length short relative to its actual barrel length. Star Bonifacio Echeverria, S.A. built it in the Spanish Basque region chambered in 9×19mm Parabellum, offering it in Largo (standard) and Corto (short) barrel lengths that share the same action and differ only in barrel and overall length. It was originally made for combat swimmers, and can be fired straight out of the water without its working parts or magazine being drained.
It entered service with Spanish and other users from the 1980s and was used during the Iran–Iraq War, among other conflicts. Star Bonifacio Echeverria went bankrupt in 1997, and Iran’s Revolutionary Guard Corps is reported to have produced the Z-84 without a licence.
Mass, length, folded length, barrel length and cyclic rate for both the Largo and Corto variants on this page come from Wikipedia’s infobox, which carries no inline citation for any of them, so all are recorded as estimated rather than verified. No manufacturer specification sheet was reachable, since Star Bonifacio Echeverria itself ceased operating in 1997. No published twist rate was found for this entry.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- Star Model Z84 · Wikipedia · 1352702163 · read 2026-09-24 · CC BY-SA 4.0
Last verified 2026-09-24 · review status: draft