SIG MKMS
- Category
- Submachine Gun
- Barrel
- 500 mm
- Weight, empty
- 3.90 kg
- Introduced
- 1933
About
What it is, and why it matters
The SIG MKMS is a Swiss submachine gun developed by Schweizerische Industrie-Gesellschaft at Neuhausen and introduced in the 1930s. A simplified military model in the SIG machine-carbine family, it used a delayed-blowback action paired with an unusually long barrel and a select-fire, hammer-fired mechanism feeding from a 40-round magazine. Its defining feature was a swiveling magazine housing, designed by Hungarian engineer Pal Kiraly, that allowed the long magazine to fold forward and lie flush along the wooden stock for carrying. Beautifully machined but expensive and slow to produce, only about 1,200 examples of the entire family were built before production ended in 1941.
The SIG machine carbines are widely regarded as among the most beautifully made submachine guns ever produced. Their swiveling magazine housing, allowing the long magazine to fold alongside the stock, was patented by Hungarian engineer Pal Kiraly, who later applied similar ideas to the Danuvia 39M.
The MKMS and MKPS were offered in several chamberings including 7.65x21mm Parabellum, 9x19mm Parabellum and 7.63x25mm Mauser. The folding magazine housing is the weapon's signature feature.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Schweizerische Industrie-Gesellschaft (SIG)
- Category
- Submachine Gun
- Country
- Switzerland
- Status
- Discontinued
- Produced
- 1933 to 1941
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 500 mm
- Overall length
- 1025 mm
- Weight, empty
- 3.90 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Delayed blowback
- Firing mechanism
- Hammer fired
- Trigger
- Single action
- Capacity
- 40
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Wood
- Finish
- Blued
BallisticsFrom the service cartridge, not a handload.
- Effective range
- 300 m
- Rate of fire
- 850 rpm
Trajectory
What the round does downrange
Solved from the muzzle figures and the bullet. The dashed rule is the effective range on the record, and the crosses are the steps the solver returned.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Folding magazine housing
Long barrel
Side ejection
Select fire
Wooden rifle stock
Standing
How it compares
Each figure against the firearms of the same type and cartridge that record it, or of the same type where that cartridge has too few. Positions are read to the nearest tenth.
| Measurement | This firearm | Median | Position |
|---|---|---|---|
| Empty weightAmong 201 9x19mm Parabellum submachine guns | 3.90 kg | 3.18 kg | Heavier than about 80% |
| Overall lengthAmong 200 9x19mm Parabellum submachine guns | 1025 mm | 723 mm | Among the longest tenth |
| Barrel lengthAmong 202 9x19mm Parabellum submachine guns | 500 mm | 213 mm | Among the longest tenth |
| Magazine capacityAmong 204 9x19mm Parabellum submachine guns | 40 | 32 | Holds more rounds than about 90% |
Answers
Questions about the SIG MKMS
How much does the SIG MKMS weigh?
The SIG MKMS weighs 3.90 kg (8.60 lb) empty.
What caliber is the SIG MKMS?
The SIG MKMS is chambered in 9x19mm Parabellum.
How many rounds does the SIG MKMS hold?
The SIG MKMS holds 40 rounds, fed from a detachable box magazine.
How long is the SIG MKMS?
The SIG MKMS is 1025 mm (40.4 in) long overall, with a 500 mm (19.7 in) barrel.
Who makes the SIG MKMS?
The SIG MKMS is made by Schweizerische Industrie-Gesellschaft (SIG) (Switzerland). It was designed by Pal Kiraly, Gotthard End, Jakob Gaetzi.
When was the SIG MKMS introduced?
The SIG MKMS was introduced in 1933 and discontinued in 1941.
How does the SIG MKMS operate?
The SIG MKMS uses a delayed blowback action, and its firing mechanism is hammer fired.
Compatibility
Which parts fit this firearm
Studio
Every part that mounts on this, resolved
Not a list the maker typed out: the answer comes from the mounts this firearm exposes and the interface each part needs, so it stays right when either one changes.
- Every part that mounts on any firearm in the catalogue
- Interface standards, platforms and fit overrides
- The same answers through the API and the MCP server
Requires a signed-in GunSpec account on the Studio plan. The answer is computed per part, so it is not part of the public record.
Provenance
What the record holds
Every figure above was taken from one of these pages. The confidence reflects how much of the record came from a page a claim can be checked against.
In service
- Swiss Police
- Switzerland
- Finnish Civil Guard
- Finland
- Vatican / Swiss Guard
- Vatican City
Provenance
Confidence in this record
80%
Stockists
Where to buy
Offers link straight to the shop. GunSpec never takes the order.
No shop has listed this firearm yet
Stock and prices come from the shops themselves. If you sell this firearm, you can list it and it appears here.
List a firearmMCP
Ask an assistant about it
The same record, reached the way a person asks for it rather than the way a program does.
Ask GunSpec
Works with
Point an MCP client at GunSpec and it answers from the catalogue rather than from memory. A free key covers the read tools.
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/firearms/sig-mkms' \ --header 'X-API-Key: your_key'{ "id": "sig-mkms", "name": "SIG MKMS", "manufacturer": { "id": "sig", "name": "Schweizerische Industrie-Gesellschaft (SIG)", "countryCode": "CH", "foundedYear": 1853, "website": null, "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-06-21 23:00:46", "updatedAt": "2026-06-21 23:00:46", "version": "5a3958877ab5dac633e5b6c9091ae6281e6ff8ccf43a78d28f24c7c2bef71055" }, "category": { "id": "submachine-gun", "name": "Submachine Gun", "description": "Automatic firearms chambered in pistol calibers" }, "country_of_origin": "CH", "year_introduced": 1933, "barrel_length_mm": 500, "weight_empty_g": 3900, "action_type": "delayed_blowback"}