Data Quality88%
MASS(Military Archive Scoring System)
ⓘ Regardless of era, the same scoring system applies to all units in the machine pistols category.
01 / Overview
Suomi KP/-31
Category
Country
Prime contractor
Production
1931–1953
Quantity
80,000
Operators
Conflicts
💰 PERFORMANCE / PRICE ASSESSMENT Methodology ↗
MACHINE PISTOLS · INTERWAR PERIOD
1
PERFORMANCE/PRICE
94
UNIT COST (2025 USD)
—
ⓘ Performance/Price and MASS score are computed across all units in the machine pistols category, regardless of era.
02 / Specs & Design
◎General4MOD.4
- First Production Year1931
- DesignerAimo Lahti
- Weight (Empty)4.6 kg
- Currently In ServiceYes
◈Cartridge & Calibre2MOD.2
- Cartridge9×19mm Parabellum, 7.65mm Parabellum
- Calibre9 mm
▣Operation7MOD.7
- Action TypeBlowback
- Fire ModesAutomatic
- Select FireYes
- Feed SystemDetachable Magazine
- Magazine Capacity20
- Drum / Belt Capacity71
- Cyclic Rate of Fire750
◇Ballistics2MOD.2
- Muzzle Velocity396 m/s
- Effective Range (point)200 m
◆Barrel & Sights3MOD.3
- Barrel Length314 mm
- Sight TypeFront blade, rear notch
- Iron SightsYes
▤Construction1MOD.1
⬢Production & Cost1MOD.1
- Total Production80,000
03 / History
SERVICE LIFESPANStill in Service
- 1931Production started
- 1932First deployment: Chaco War
- 1940Sale: Bulgaria (5,000 units)
- 1953Production ended
95
years in service
22
years in production
80,000
units produced
20
countries operating
ⓘ The producing country still actively operates it. 4 countries retired it.
04 / Conflicts
SUOMI KP/-31 · CONFLICTS SERVED IN0% win·60% loss
Total Conflicts
5
Victories
0
Ongoing
0
Losses
3
1948–19491948 Arab–Israeli War—→1944–1945Lapland WarDecisive victory→1941–1944Continuation WarDecisive victory→1939–1940Winter WarDecisive victory→1938–Integralist Uprising—→
ⓘ Shown only from conflicts recorded in our database.
05 / Operators
Operator Inventory9country · 67,742units
67,742active
Suomi KP/-31SALES4records
| Year | Buyer | Quantity | Amount | Present Value (2025) |
|---|---|---|---|---|
| 1940 |  Bulgaria | 5,000 | — | — |
| 1940 |  Croatia | 500 | — | — |
| — |  Germany | 3,042 | — | — |
| — |  Estonia | 485 | — | — |
ⓘ "Present Value" is an estimated amount adjusted for inflation.
06 / MASS Score
MACHINE PISTOLS RANKING Machine Pistols · Interwar Period
MASS RANKINGSMASS ↗
3MACHINE PISTOLS1INTERWAR PERIOD · MACHINE PISTOLS20FINLAND · ALL WEAPONS2PERFORMANCE/PRICE · MACHINE PISTOLS
ⓘ Rankings are within theMachine Pistolscategory.
📖 TERMS ON THIS PAGE4terms
A type of firearm action where the breech is not locked and the cartridge case expands to seal the breech, using case expansion and pressure to retain gases.
A firearm feed system where ammunition is stored in a separate container (magazine) that can be removed and replaced, enabling rapid reloading.
Adjustable metal aiming devices on firearms, consisting of a front post and rear notch, used without magnification.
Select fire is a fire selector mechanism on a firearm that lets the shooter choose the firing mode, such as semi‑automatic, burst, or fully automatic.
These terms are listed automatically because they appear on this page.full encyclopedia →
📚 Sources