Image credit
- Title
- File:MP-L WALTHER 9MM.jpg
- Author
- Springfield Armory Museum
- Licence
- Public domain
- Source
- https://commons.wikimedia.org/wiki/File:MP-L_WALTHER_9MM.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 260 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 kg6.614 lbverifiedsourceMPL, as published on Modern Firearms.
- v_recoil0.8935 m/s2.931 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
- capacity32verifiedsource32-round detachable box magazine, as published on Modern Firearms.
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 260 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 260 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
- n32verifiedsource32-round detachable box magazine, as published on Modern Firearms.
- rpm550 rpmverifiedsourceAs published on Modern Firearms, common to both MPK and MPL.
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
MPK
The short-barreled version of the Walther MP, standing for Maschinenpistole Kurz ("short"), with a shorter barrel and stock than the MPL.
- Mass, empty
- 2.83 kg6.239 lbsource
As published on Modern Firearms.
- Length
- 659 mm25.94 insource
Stock extended, as published on Modern Firearms.
- Length, folded
- 381 mm15.00 insource
Stock folded, as published on Modern Firearms.
- Barrel length
- 173 mm6.811 insource
As published on Modern Firearms.
- Effective range
From the Wikipedia infobox; no inline citation is given there.
| Variant | Years | Changes |
|---|---|---|
| MPK | — | Mass, empty, Length, Length, folded, Barrel length, Effective range |
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
- Roles
- Designed in
- Germany
- Produced in
- Introduced
- 1963
- Production
- 1963–1983
Dimensions and mass
- Mass, empty
- 3 kg6.614 lbsource
MPL, as published on Modern Firearms.
- Magazine, empty
- not recorded
- Length
- 746 mm29.37 insource
MPL, stock extended, as published on Modern Firearms.
- Length, folded
- 462 mm18.19 insource
MPL, stock folded, as published on Modern Firearms.
- Width
- not recorded
- Height
- not recorded
- Barrel length
- 260 mm10.24 insource
MPL, as published on Modern Firearms.
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
- 9x19mm Parabellumprimary32 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.
- Walther MP746 mm29.37 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. Walther MP 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 Walther MP is a blowback-operated submachine gun Carl Walther GmbH produced in West Germany from 1963 to 1983, offered in two sizes sharing the same action, cartridge and magazine: the longer MPL (Maschinenpistole Lang) and the shorter MPK (Maschinenpistole Kurz). Its bolt design is unusual, similar in concept to but distinct from a telescoping bolt: a hollow tubular weight rides above the barrel, connected to a steel block underneath that performs the bolt’s normal functions, an arrangement that let Walther fit a relatively long barrel into a compact overall weapon.
The West German Navy adopted the MPL, and some domestic police forces, including the West Berlin Police, adopted the MPL, the MPK or both, but Heckler & Koch’s MP5 eventually eclipsed the Walther MP’s domestic sales and led to its discontinuation. It found a wider export market, with countries including Brazil, Colombia and Venezuela buying the compact MPK specifically, and it was carried by United States Navy SEALs in Vietnam and by Delta Force during Operation Eagle Claw. It has also been documented in service across a range of other conflicts and internal security operations from the 1960s through the 1980s, including the Portuguese Colonial War, the Rhodesian Bush War and the Lebanese Civil War.
Mass, length and barrel length figures for both variants, along with cyclic rate and magazine capacity, come from a specialist firearms reference site and are recorded as verified. Effective range for each variant is recorded as estimated, since Wikipedia’s infobox carries no citation for those figures. No published twist rate was found for either variant, and no photograph of the shorter MPK appears on this site.
References
This entry's own bibliography. Every citation key on this page resolves into this list.
- Walther MP · Wikipedia · 1359206070 · read 2026-09-24 · CC BY-SA 4.0
- Walther MPL / MPK submachine guns · Modern Firearms · read 2026-09-24
Last verified 2026-09-24 · review status: draft