Barrett M82A1 family: root design and variant changes

The Barrett M82A1 is the root design in this catalogue family. Introduced in 1982¹, it is a short recoil operated rifle chambered for .50 BMG. The catalogue records an empty weight of 14,800 g, overall length of 1,448 mm, barrel length of 737 mm, 10-round detachable box magazine, muzzle velocity of 853 m/s, muzzle energy of 18,000 J, effective range of 1,800 m and maximum range of 4,000 m.

That makes the family useful to compare figure by figure. The later M107 and M107A1 stay within the same basic pattern: the same .50 BMG chambering, the same 1,448 mm overall length, the same 737 mm barrel, the same 10-round capacity and the same recorded 853 m/s muzzle velocity. What changes most clearly in the catalogue is weight. The M107 is listed at 12,900 g² empty, and the M107A1 at 12,430 g³, against the M82A1 baseline of 14,800 g.

This section therefore treats the M82A1 as the reference point, then follows how later catalogued variants altered selected figures without departing from the original mechanical and dimensional envelope shown by the chart below.

The baseline dimensions and mechanism

The catalogue sets the Barrett M82A1 baseline as a short recoil, rotating bolt rifle built around steel throughout its main structure. Its receiver is steel, its barrel is steel and its stock is steel, all with a manganese phosphate finish. The barrel specification is also explicit: 381 mm¹ twist with 8 grooves. Those details matter because they define the root mechanical pattern before later variants are compared by weight and designation.

Across the family, the main external dimensions are notably stable. The M82A1, M107 and M107A1 are all listed at 1,448 mm overall length and 737 mm barrel length. The chart below reflects that point directly, showing no barrel length change between the three catalogue entries.

The same continuity appears in the operating envelope. All 3 rifles are chambered for .50 BMG, all use a 10 round detachable box magazine, and all are recorded at 853 m/s muzzle velocity where listed. In other words, the family does not move by altering length, barrel or magazine pattern. It stays within the same basic dimensions and ballistic baseline, which makes later differences, especially in empty weight, easier to isolate and interpret.

Source: GET /v1/firearms/compare?ids=barrett-m82a1,barrett-m107a1,barrett-m107

The data in this chart

Firearm	Barrel length (mm)
Barrett M107	737
Barrett M107A1	737
Barrett M82A1	737

What the M107 changed, and what it did not

The M107 is the catalogue’s 2002¹ military-standardised branch of the M82A1, and the figures indicate continuity more than redesign. Both rifles are short recoil operated and chambered for .50 BMG. Both keep the same 1,448 mm overall length, 737 mm barrel length, 10-round detachable box magazine, 853 m/s muzzle velocity and 1,800 m effective range.

That consistency matters because it shows that the Army designation did not alter the family’s basic ballistic and dimensional envelope. In catalogue terms, the M107 remains the same size class and uses the same cartridge with the same recorded external performance.

The main numerical change is weight. The M82A1 is listed at 14,800 g empty, while the M107 is 12,900 g² empty. That is a reduction of 1,900 g⁴, or 1.9 kg. The chart below makes this the clearest point of separation between the two records.

The historical sources in the brief describe the relationship in similar terms. One passage states that the M107 systems “represent only a slightly different version of the excellent Barrett design” (source). Within the catalogue figures, that description fits: the M107 changes the recorded empty weight, but not the core dimensions, capacity, cartridge or stated range.

Source: GET /v1/firearms/compare?ids=barrett-m82a1,barrett-m107a1,barrett-m107

The data in this chart

Firearm	Empty weight (g)
Barrett M82A1	14,800
Barrett M107	12,900
Barrett M107A1	12,430

What the M107A1 changed

The M107A1, introduced in 2011¹, marks the clearest numerical change within the catalogued M82A1 family. In the main external and ballistic figures, it stays within the same pattern as the root Barrett M82A1: overall length remains 1,448 mm, barrel length 737 mm, magazine capacity 10 rounds, muzzle velocity 853 m/s and effective range 1,800 m. It also remains a short recoil rifle chambered for .50 BMG.

What changes is empty weight. The M107A1 is listed at 12,430 g³. Against the M82A1’s 14,800 g, that is a reduction of 2,370 g⁴. Against the M107, listed at 12,900 g, it is 470 g lighter. The chart below makes that shift clear: the family’s dimensions and cartridge stay fixed, while mass falls in steps across the later variants.

That matters because it shows the M107A1 as a refinement rather than a new layout. The catalogue description attributes the reduction to aluminium and titanium components while retaining full .50 BMG capability. In family terms, the M107A1 keeps the established 1,448 mm by 737 mm envelope and 10-round format, but moves the design furthest from the M82A1 baseline on weight alone.

Source: GET /v1/firearms/compare?ids=barrett-m82a1,barrett-m107a1,barrett-m107

The data in this chart

Firearm	Empty weight (g)
Barrett M82A1	14,800
Barrett M107	12,900
Barrett M107A1	12,430

The cartridge as the family constant

The family comparison is anchored by .50 BMG, introduced in 1921⁵. In the catalogue it is the same chambering for the M82A1, M107 and M107A1, which matters because it holds several core figures steady across the line.

Its recorded dimensions are 12.98 mm bullet diameter, 99.31 mm case length and 138.43 mm overall cartridge length. It is a rimless, bottleneck brass case with a large rifle primer, and the catalogue gives a maximum pressure of 379 MPa, also published as 54923 psi. The typical bullet weight is 42 g.

With that cartridge unchanged, the three rifles keep the same 737 mm¹ barrel length, 10 round magazine capacity and 853 m/s muzzle velocity where recorded. That does not mean the rifles are identical, but it does show that the family’s main ballistic and feed envelope was preserved while other changes, especially weight, were made elsewhere.

The catalogue also records a typical muzzle energy of 18,000 J for .50 BMG. That figure is under review, so it is best treated here as the record currently holds it, not as the basis for a broader conclusion.

Adoption and naming across the family

The naming history matters because the catalogue treats the Barrett M82A1 as one root design that entered service under several labels, rather than as a series of mechanically separate rifles. Its record lists 20¹ catalogued users, and the service names vary by country and branch. In British service it appears as L82A1, and in German service as G82. The same base record also notes adoption by Sweden in 1989, by the United States Air Force in 1990 as SASR, by the United States Marine Corps in 1990 as M82A3 SASR, and by the United States Army in 2002 as M107.

That 2002 Army designation is the point where the family name shifts most clearly in the catalogue. The separate Barrett M107 entry is not presented as a new cartridge or action type, but as the standardised Army form of the M82A1 pattern. As one summary passage puts it, the M107 and M82A1 sit in the same “Rifle family line” (source).

The Barrett M107A1 extends that naming chain again. Its record adds United States Army adoption in 2011 under the M107A1 designation, showing a later, lighter catalogue variant rather than a break from the family.

For the full family records and figures, see the M82A1 catalogue page.

Materials and densities

Sources and methods

Footnotes

1. GunSpec catalogue record for the Barrett M82A1, which cites barrett.net, militaryfactory.com, weaponsystems.net, globalmilitary.net. In the API: firearms reference. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

2. GunSpec catalogue record for the Barrett M107, which cites militaryfactory.com, americancop.com. In the API: firearms reference. ↩ ↩²

3. GunSpec catalogue record for the Barrett M107A1, which cites en.wikipedia.org, militaryfactory.com, en.wikipedia.org. In the API: firearms reference. ↩ ↩²

4. Method, comparisons: a difference is one catalogue figure minus another of the same kind, in the same unit. Comparisons. ↩ ↩²

5. GunSpec catalogue record for the .50 BMG, which cites en.wikipedia.org. In the API: calibers reference and ammunition reference. ↩