Image credit
- Title
- File:JGSDF Type 89 Assault Rifle 20100418-01.jpg
- Author
- Crescent moon at Japanese Wikipedia(attribution required)
- Licence
- CC BY 3.0
- Source
- https://commons.wikimedia.org/wiki/File:JGSDF_Type_89_Assault_Rifle_20100418-01.jpg
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- v920.0 m/s3,018 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
1 of 2 inputs link to their source.
How Muzzle velocity is calculated
linear interpolation between the two nearest sourced barrel lengths
Inputs
- v at 368.3 mm905.3 m/s2,970 fpsverifiedsourceTable 2-1, muzzle velocity for the M4: 2,970 fps.
- v at 508 mm944.9 m/s3,100 fpsverifiedsourceTable 2-1, muzzle velocity for the M16A2: 3,100 fps. The M855 is the manual's service round for that rifle.
Assumptions
- Velocity is assumed to vary linearly between the two measurements. Over a short span that is a reasonable reading of the data; it is not a law.
2 of 2 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.
3 of 4 inputs link to their source.
How Free recoil is calculated
E_recoil = ½ · m_firearm · v_recoil²
Inputs
- m_firearm3.5 kg7.716 lbestimatedsourcefrom the infobox; no inline citation is given there.
- v_recoil1.056 m/s3.465 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
- capacity30estimatedsource20 or 30-round detachable STANAG magazines, from the infobox, uncited there.
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
- m4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- v920.0 m/s3,018 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
1 of 2 inputs link to their source.
How Sectional density is calculated
SD = mass(gr) / (7000 · diameter(in)²)
Inputs
- mass4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- diameter5.7 mm0.2244 inestimatedsourceNo free NATO dimensional standard is published. The C.I.P. datasheet for the .223 Remington, which shares this bullet, gives a cartridge-maximum bullet diameter of 5.70 mm.
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
- mass4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- velocity920.0 m/s3,018 fpsestimatedInterpolated between sourced measurements at 368.3 mm and 508 mm.
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
- n30estimatedsource20 or 30-round detachable STANAG magazines, from the infobox, uncited there.
- rpm750 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
Type 89-F
The folding-stock version of the Type 89, sharing the same action, cartridge and barrel but built with a side-folding stock rather than a fixed one.
- Length
stock folded, from the infobox, uncited there.
| Variant | Years | Changes |
|---|---|---|
| Type 89-F | — | 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
- Rifle
- Action
- Self-loading
- Fire modes
- Semi-automatic
- Burst
- Fully automatic
- Operating system
- Gas, short-stroke piston
- Roles
- Designed in
- Japan
- Produced in
- Introduced
- 1989
- Production
- not recorded
Dimensions and mass
- Mass, empty
from the infobox; no inline citation is given there.
- Magazine, empty
- not recorded
- Length
fixed-stock configuration, from the infobox, uncited there.
- Length, folded
- not recorded
- Width
- not recorded
- Height
- not recorded
- Barrel length
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
Chamberings
- 5.56x45mm NATOprimary30 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.
- Howa Type 89916 mm36.06 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. Howa Type 89 records no height, so its outline is drawn at the type's proportion. That height is part of the shape, not a measurement.
Gallery
Image credit
- Title
- Japan Ground Self-Defense Force members participate in apprehension training during Active Shield 26
- Author
- Lance Cpl. Ella Cadby
- Licence
- Public domain
- Source
- https://www.dvidshub.net/image/9370839/japan-ground-self-defense-force-members-participate-apprehension-training-during-active-shield-26
- Note
- Work of the United States Government, uncopyrighted under 17 U.S.C. §105: photographed for the Marines (Marine Corps Air Station Iwakuni), VIRIN 251024-M-MN099-1028. DVIDS states no separate licence per asset.
Detail
The Type 89 replaced the Type 64, a 7.62×51mm battle rifle Japan had carried for twenty-five years by the time an assault-rifle replacement entered service in 1989. The switch followed a pattern set decades earlier elsewhere: as armies moved from full-power battle-rifle cartridges to intermediate rounds, Japan brought its own service rifle in line with 5.56×45mm NATO rather than continue building around the heavier 7.62mm case.
Howa builds it under Japan’s long-standing arms-export ban, which has kept the Type 89 a rifle built solely for Japanese service; it has never been exported or licensed abroad, unlike most rifles adopted by a similarly sized armed force. That constraint has kept total production modest compared with Western rifles built for both domestic and export markets, though the article gives no production total to compare directly.
Mechanically the rifle follows the short-stroke gas piston and rotating bolt layout common to many assault rifles of its generation, offered with either a fixed polymer stock or, as the Type 89-F variant recorded here, a side-folding stock that shortens the rifle without changing its action, barrel or cartridge.
Every figure in this entry traces to the Wikipedia infobox without an inline citation and is recorded as
estimated. No twist rate is published.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- Howa Type 89 · Wikipedia · 1372292102 · read 2026-09-09 · CC BY-SA 4.0
Last verified 2026-09-09 · review status: agent-populated