M40
- Category
- Sniper Rifle
- Barrel
- 610 mm
- Weight, empty
- 4.10 kg
- Introduced
- 1966
About
What it is, and why it matters
The M40 is a bolt-action sniper rifle adopted by the United States Marine Corps in 1966. Built on the Remington Model 700 short action and chambered in 7.62x51mm NATO, it featured a 24-inch heavy match barrel, a one-piece wooden stock, and a 5-round internal box magazine, typically mounted with a Redfield 3-9x Accurange variable scope. Introduced during the Vietnam War, the M40 became the foundation of the USMC sniper rifle lineage for the following four decades.
Adopted on April 7, 1966, the M40 gave USMC snipers a purpose-built precision rifle during the Vietnam War, where legendary marksmen such as Carlos Hathcock used it to record long-range engagements.
Factory-produced base model later rebuilt and refined by USMC armorers at Marine Corps Base Quantico into the M40A1 and subsequent variants. Production of the original M40 configuration ended in 1977.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Remington Arms
- Category
- Sniper Rifle
- Country
- United States
- Status
- Discontinued
- Produced
- 1966 to 1977
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 610 mm
- Overall length
- 1117 mm
- Weight, empty
- 4.10 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Bolt action
- Firing mechanism
- Striker fired
- Trigger
- Single action
- Capacity
- 5
- Magazine
- Fixed box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Wood
- Finish
- Parkerized
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 777 m/s
- Muzzle energy
- 3457 J
- Effective range
- 800 m
- Maximum range
- 1000 m
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.
Heavy match barrel
One piece wooden stock
Telescopic sight
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 80 7.62x51mm NATO sniper rifles | 4.10 kg | 5.04 kg | Lighter than about 90% |
| Overall lengthAmong 80 7.62x51mm NATO sniper rifles | 1117 mm | 1116 mm | Near the median |
| Barrel lengthAmong 80 7.62x51mm NATO sniper rifles | 610 mm | 559 mm | Longer than about 70% |
| Magazine capacityAmong 80 7.62x51mm NATO sniper rifles | 5 | 15 | Holds fewer rounds than about 80% |
Answers
Questions about the M40
How much does the M40 weigh?
The M40 weighs 4.10 kg (9.04 lb) empty.
What caliber is the M40?
The M40 is chambered in 7.62x51mm NATO.
How many rounds does the M40 hold?
The M40 holds 5 rounds, fed from a fixed box magazine.
How long is the M40?
The M40 is 1117 mm (44.0 in) long overall, with a 610 mm (24.0 in) barrel.
Who makes the M40?
The M40 is made by Remington Arms (United States). It was designed by Remington Arms / USMC Marksmanship Training Unit.
When was the M40 introduced?
The M40 was introduced in 1966 and discontinued in 1977.
How does the M40 operate?
The M40 uses a bolt action, and its firing mechanism is striker 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 Marine Corps
- 1966
Provenance
Confidence in this record
86%
Stockists
Where to buy
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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/m40-sniper-rifle' \ --header 'X-API-Key: your_key'{ "id": "m40-sniper-rifle", "name": "M40", "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": "sniper-rifle", "name": "Sniper Rifle", "description": "Precision rifles optimized for long-range accuracy" }, "country_of_origin": "US", "year_introduced": 1966, "barrel_length_mm": 610, "weight_empty_g": 4100, "action_type": "bolt_action"}