M40A1
- Category
- Sniper Rifle
- Barrel
- 610 mm
- Weight, empty
- 6.58 kg
- Introduced
- 1977
About
What it is, and why it matters
The M40A1 is the second generation of the USMC's M40 sniper rifle series, adopted in 1977 as a comprehensive rebuild of the original M40. Based on the Remington Model 700 bolt-action receiver, the M40A1 replaced the original wooden stock with a McMillan A1 fiberglass stock finished in green and earthtone red camouflage, and swapped the Redfield variable-power scope for a fixed 10x Unertl target scope. The 24-inch Atkinson barrel was replaced with a heavier 24-inch stainless steel barrel by Atkinson or later Hart, providing improved accuracy and barrel life. Like all M40 variants, each M40A1 was individually hand-built by USMC armorers at the Precision Weapons Section, Marine Corps Base Quantico, rather than factory mass-produced. The M40A1 fed from a 5-round internal box magazine and was capable of sub-MOA accuracy, serving as the USMC's primary sniper rifle for over two decades across multiple conflicts.
The M40A1 served as the USMC's standard sniper rifle for over two decades and became synonymous with Marine Corps scouting and sniping. Carlos Hathcock, the legendary USMC sniper with 93 confirmed kills in Vietnam, used the original M40 and was instrumental in the development program that led to the M40A1. The rifle's iconic combination of the Remington 700 action, McMillan fiberglass stock, and Unertl 10x scope defined what a military sniper rifle looked like for a generation.
The M40A1 conversion program began in the early-to-mid 1970s at Quantico, where armorers rebuilt existing M40 rifles with new components. The 10x Unertl scope became the iconic optic of USMC snipers for decades. The stainless steel barrel provided better corrosion resistance and accuracy over the original chrome-moly barrel. The M40A1 served from 1977 until it was replaced by the M40A3 beginning in 2001. In June 2006, one of the two initial M40A1 prototypes was recovered when an Iraqi sniper was killed by a USMC sniper, revealing that the rifle had been captured and was being used against Coalition forces. The total weight of 14.5 lbs (6.58 kg) includes the Unertl scope.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Remington Arms
- Category
- Sniper Rifle
- Country
- United States
- Status
- Out of production
- Produced
- 1977 to 2001
- Variant of
- Predecessor
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 610 mm
- Overall length
- 1118 mm
- Weight, empty
- 6.58 kg
- Weight, loaded
- 7.20 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Bolt action
- Firing mechanism
- Striker fired
- Trigger
- Single stage
- Trigger pull
- 27.0 N
- Capacity
- 5
- Magazine
- Fixed box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Stainless steel
- Stock
- Fiberglass
- Finish
- Matte black
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 777 m/s
- Muzzle energy
- 2867 J
- Effective range
- 915 m
- Maximum range
- 3725 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.
Free floating barrel
Heavy barrel
Fiberglass stock
Aluminum bedding block
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 | 6.58 kg | 5.04 kg | Heavier than about 90% |
| Overall lengthAmong 80 7.62x51mm NATO sniper rifles | 1118 mm | 1116 mm | Longer than about 60% |
| 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 M40A1
How much does the M40A1 weigh?
The M40A1 weighs 6.58 kg (14.51 lb) empty and 7.20 kg (15.87 lb) loaded.
What caliber is the M40A1?
The M40A1 is chambered in 7.62x51mm NATO.
How many rounds does the M40A1 hold?
The M40A1 holds 5 rounds, fed from a fixed box magazine.
How long is the M40A1?
The M40A1 is 1118 mm (44.0 in) long overall, with a 610 mm (24.0 in) barrel.
Who makes the M40A1?
The M40A1 is made by Remington Arms (United States).
When was the M40A1 introduced?
The M40A1 was introduced in 1977 and discontinued in 2001.
How does the M40A1 operate?
The M40A1 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
- 1977
Provenance
Confidence in this record
85%
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/m40a1' \ --header 'X-API-Key: your_key'{ "id": "m40a1", "name": "M40A1", "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": 1977, "barrel_length_mm": 610, "weight_empty_g": 6580, "action_type": "bolt_action"}