Image credit
- Title
- File:VektorR4.png
- Author
- User:Katangais(attribution required)
- Licence
- CC BY 2.5
- Source
- https://commons.wikimedia.org/wiki/File:VektorR4.png
How Muzzle energy is calculated
E = ½ · m · v²
Inputs
- m4.018 g62.01 grverifiedsource62 gr as published, converted to grams.
- v931.3 m/s3,055 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_firearm4.3 kg9.480 lbestimatedsourcecited by the infobox to Jane's Infantry Weapons 1997-98, a print reference not independently consulted for this survey; a book citation is never `verified` here.
- v_recoil0.8702 m/s2.855 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
- capacity35estimatedsource35-round detachable magazine, 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.
- v931.3 m/s3,055 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.
- velocity931.3 m/s3,055 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
- n35estimatedsource35-round detachable magazine, from the infobox, uncited there.
- rpm675 rpmestimatedsourcemidpoint of a published 600-750 rounds/min range, from 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
R5
A shorter-barrelled carbine version of the R4 for mechanised infantry and support troops, keeping the same action, cartridge and magazine.
R6
The shortest-barrelled member of the family, a submachine-gun-length carbine built on the same R4 action for vehicle crews and specialist troops.
| Variant | Years | Changes |
|---|---|---|
| R5 | — | no spec change |
| R6 | — | no spec change |
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
- Fully automatic
- Operating system
- Gas, long-stroke piston
- Roles
- Designed in
- South Africa
- Produced in
- Introduced
- 1980
- Production
- not recorded
Dimensions and mass
- Mass, empty
cited by the infobox to Jane's Infantry Weapons 1997-98, a print reference not independently consulted for this survey; a book citation is never `verified` here.
- Magazine, empty
- not recorded
- Length
stock extended, from the infobox, uncited there.
- Length, folded
- not recorded
- Width
stock extended, from the infobox, uncited there.
- Height
from the infobox, uncited there.
- 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 NATOprimary35 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.
- Vektor R4877 mm34.53 in
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.
Lineage
This design
- Derived from IWI Galil
Gallery
Image credit
- Title
- File:Vektor R4 Upgraded.png
- Author
- Winters229(attribution required)
- Licence
- CC BY-SA 4.0
- Source
- https://commons.wikimedia.org/wiki/File:Vektor_R4_Upgraded.png
Detail
The R4 replaced South Africa’s R1, a locally built FN FAL variant, when it entered service in 1980. Rather than design a new rifle from nothing, Lyttelton Engineering Works built it as a licensed variant of Yisrael Galili’s IMI Galil, itself already a Kalashnikov-derived design, and reworked it for South African conditions and manufacture. The stock and magazine were remade in high-strength polymer rather than the Galil’s original materials, the stock was lengthened for the average South African soldier’s build, and the folding carrying handle over the receiver was dropped along with a number of changes to the internal operating mechanism.
Local licensed production mattered for reasons beyond simple economy: South Africa built the R4 and its ammunition domestically through most of its production run under circumstances that made buying rifles abroad far harder than for most armies of its size, though the cited article does not spell out that context directly.
Denel Land Systems, the successor to Lyttelton Engineering Works, still lists the R4 family among its products. Two carbine derivatives recorded here as variants, the R5 and the shorter R6, share the R4’s gas-operated action and 5.56mm chambering on progressively shorter barrels; a semi-automatic-only civilian line sold as the LM4, LM5 and LM6 is not modelled here.
This entry’s length, barrel length, width, height, cyclic rate and effective range trace to the Wikipedia
infobox without an inline citation and are recorded as estimated; the weight figure is cited there to
Jane’s Infantry Weapons, a printed reference this survey did not consult directly, so it too remains
estimated rather than verified. No twist rate is published.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- Vektor R4 · Wikipedia · 1372985246 · read 2026-09-09 · CC BY-SA 4.0
Last verified 2026-09-09 · review status: agent-populated