Pedersen Device M1918
- Category
- Rifle
- Barrel
- Not recorded
- Weight, empty
- 964 g
- Introduced
- 1918
About
What it is, and why it matters
The Pedersen Device M1918 is a semi-automatic conversion unit that replaced the standard bolt of a specially modified M1903 Springfield rifle, transforming the bolt-action service rifle into a blowback-operated, semi-automatic carbine firing a low-power .30-caliber pistol-sized cartridge. Designed by John D. Pedersen of Remington during World War I, it was issued the deliberately misleading official nomenclature 'Automatic Pistol, Caliber .30, Model of 1918' to preserve wartime secrecy. Fed by a 40-round stick magazine inserted at an angle on the upper right of the receiver, the device let a rifleman lay down roughly 100 aimed shots per minute across no man's land, then reinstall the standard bolt for long-range bolt-action fire. The Armistice arrived before it could see combat, and almost all of the roughly 65,000 devices produced were later destroyed, making surviving examples among the rarest of American military firearms.
Demonstrated to US Army ordnance officers in October 1917, the device so impressed observers that it was rushed into secret production under a pistol cover-name. Pedersen reportedly fired rapid semi-automatic strings from a rifle that moments earlier had been a slow bolt-action, stunning the officers present. The Armistice of November 1918 rendered the weapon's surprise-assault role moot, and it never saw combat.
The Pedersen Device is not a complete firearm on its own; it drops into the action of a modified rifle (the M1903 Mark I) featuring an oval ejection port, altered sear and cut-off. The M1918 designation covers the Mark I units built for the M1903 Springfield; a Mark II for the M1917 Enfield was ordered but the contract was canceled at the Armistice. After the war the US Army scrapped the vast majority of devices in the early 1920s.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Remington Arms
- Category
- Rifle
- Country
- United States
- Status
- Discontinued
- Produced
- 1918 to 1920
DimensionsAs issued, without a magazine or an optic.
- Weight, empty
- 964 g
- Weight, loaded
- 1.42 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- 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
- Slide
- Steel
- Barrel
- Steel
- Finish
- Blued
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 396 m/s
- Muzzle energy
- 406 J
- Effective range
- 90 m
- Maximum range
- 500 m
- Rate of fire
- 100 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.
No load solved for this record yetThe flight path is computed from a cartridge and a bullet. This record has no ammunition filed against its chambering, so there is nothing to solve.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
- Drop in bolt replacement
- Converts bolt action to semi auto
40 round stick magazine- Side mounted angled magazine
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 1,612 rifles | 964 g | 3.50 kg | Among the lightest tenth |
| Magazine capacityAmong 1,611 rifles | 40 | 5 | Holds more rounds than about 90% |
Its place in the rankings
Answers
Questions about the Pedersen Device M1918
How much does the Pedersen Device M1918 weigh?
The Pedersen Device M1918 weighs 964 g (2.13 lb) empty and 1.42 kg (3.12 lb) loaded.
What caliber is the Pedersen Device M1918?
The Pedersen Device M1918 is chambered in 7.65x20mm Longue.
How many rounds does the Pedersen Device M1918 hold?
The Pedersen Device M1918 holds 40 rounds, fed from a detachable box magazine.
Who makes the Pedersen Device M1918?
The Pedersen Device M1918 is made by Remington Arms (United States). It was designed by John D. Pedersen.
When was the Pedersen Device M1918 introduced?
The Pedersen Device M1918 was introduced in 1918 and discontinued in 1920.
How does the Pedersen Device M1918 operate?
The Pedersen Device M1918 uses a 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
- United States Army
- 1918
Provenance
Confidence in this record
82%
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/pedersen-m1918' \ --header 'X-API-Key: your_key'{ "id": "pedersen-m1918", "name": "Pedersen Device M1918", "manufacturer": { "id": "remington", "name": "Remington Arms", "countryCode": "US", "foundedYear": 1816, "website": "https://www.remarms.com", "logoUrl": null, "description": null, "status": "active", "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-02-11 23:44:38", "updatedAt": "2026-02-18 03:40:45", "version": "f839df62af811e3e261014e3302be8a7e112b5d78fb2f9f7bfad68d74817c9c8" }, "category": { "id": "rifle", "name": "Rifle", "description": "Long-barreled firearms designed for accurate shooting" }, "country_of_origin": "US", "year_introduced": 1918, "barrel_length_mm": null, "weight_empty_g": 964, "action_type": "blowback"}