The catalogue records the 12 Gauge as a cartridge introduced in 18701, with a rimmed, straight case, polymer case material and a shotshell primer. Its recorded dimensions are an 18.53 mm bullet diameter, 20.62 mm neck diameter, 21.59 mm base diameter and 22.5 mm rim diameter. Case length is 70 mm, and recorded overall length is also 70 mm.
Those figures set out the geometry this article refers back to when it looks at loads and firearms chambered for the cartridge. They show a short, straight, rimmed shotshell pattern that appears across a very large part of the catalogue. The pressure record is also part of that baseline: the catalogue lists a maximum pressure of 74 MPa and 11500 psi. That pressure figure is under review in the catalogue, because its sources disagree, so it is best read here as the current record rather than as a settled reference value.
This section therefore starts with the cartridge dimensions and pressure record, then uses that baseline to frame the catalogue’s load figures and the spread of firearms chambered for 12 Gauge.
What the catalogue records as a typical 12 Gauge load
The 12 Gauge cartridge record gives a baseline for a typical load of 32 g1, 400 m/s2 and 2560 J. In this article, those figures serve as the reference point for the firearm records that follow, because they describe the cartridge entry itself rather than any one shotgun.
A short summary of the catalogue baseline is:
| Typical 12 Gauge load | Figure |
|---|---|
| Projectile weight | 32 g |
| Muzzle velocity | 400 m/s |
| Muzzle energy | 2560 J |
That matters when reading the firearm sample later. Some shotguns in the catalogue have their own recorded muzzle velocity figures, and those can be compared against this cartridge baseline as firearm specific records. They should not be treated as a complete load table for the calibre.
At present, the catalogue returned no separate load list for 12 Gauge in the article data. The held load breakdown is therefore not available from the present record. The article should say that plainly, rather than infer a spread of shot, slug or buckshot loads that the current record does not supply.
Representative firearms chambered for 12 Gauge
The catalogue lists 12 Gauge in 6801 firearms, and the representative set here shows how widely that chambering spans both time and mechanism. At the early end is the Browning Auto-5, introduced in 19022, a long-recoil self-loading shotgun. At the recent end is the Beretta A300 Ultima Patrol, introduced in 20233, a gas-operated self-loading design.
Between those points, the same cartridge appears in several distinct layouts and operating systems. The Benelli M1014, introduced in 1999, and the Beretta 1301 Tactical, introduced in 2014, are both gas-operated self-loaders. The Benelli Super Black Eagle 3, introduced in 2017, represents inertia operation. The Mossberg 590A1, introduced in 19874, represents pump action. The IWI Tavor TS12, introduced in 2018, adds a bullpup format, while the Mossberg 940 Pro Tactical, introduced in 2021, returns to a modern gas-operated self-loader.
This spread, from 1902 to 2023, matters because it shows that 12 Gauge is not tied to one period or one action type. In the catalogue record, it persists across long-recoil, pump-action, inertia-operated and bullpup firearms as well as multiple generations of gas-operated shotguns.
Size, weight and capacity across current examples
The same 12 Gauge chambering appears in markedly different firearm layouts. In this sample, recorded empty weight runs from 2880 g3 for the Beretta 1301 Tactical to 3856 g2 for the Browning Auto-5, a spread of 976 g5. The Beretta A300 Ultima Patrol is listed at 3232 g, but that figure is under review and should be read as the current record rather than used as a ranking point.
Overall length varies even more. The shortest example here is the IWI Tavor TS12 at 720 mm6, while the Browning Auto-5 is 1270 mm7 long. Barrel lengths in the same group run from 470 mm on the Beretta 1301 Tactical, Benelli M1014, TS12 and Mossberg 940 Pro Tactical, to 711 mm on the Benelli Super Black Eagle 3 and Browning Auto-5.
Capacity also spans a wide range. The Super Black Eagle 3 is listed at 3 rounds8, the 1301 Tactical and Auto-5 at 4 rounds, the M1014 at 5 rounds4, the A300 Ultima Patrol and 940 Pro Tactical at 7 rounds, the Mossberg 590A1 at 8 rounds9, and the TS12 at 15 rounds. That spread shows how one cartridge record supports long-recoil, pump-action, gas-operated, inertia-operated and bullpup designs.
Recorded muzzle velocity and effective range in the sample
Within this sample, recorded muzzle velocity is available for Beretta 1301 Tactical, Beretta A300 Ultima Patrol, Browning Auto-5 and Mossberg 590A1. The figures run from 381 m/s3 to 457 m/s9 in the present record, as the chart below shows.
| Firearm | Muzzle velocity |
|---|---|
| Beretta 1301 Tactical | 381 m/s |
| Beretta A300 Ultima Patrol | 381 m/s |
| Browning Auto-5 | 396 m/s |
| Mossberg 590A1 | 457 m/s |
That gives a recorded spread of 76 m/s5 between the lowest and highest figures in this subset. The two Beretta self-loaders share the same listed value, the Auto-5 sits 15 m/s above them, and the 590A1 is 61 m/s above the Auto-5.
Recorded effective range is broader across the sample than recorded muzzle velocity. Beretta 1301 Tactical, Beretta A300 Ultima Patrol, Browning Auto-5, IWI Tavor TS12 and Mossberg 590A1 are listed at 40 m, Mossberg 940 Pro Tactical at 45 m10, and Benelli M1014 and Benelli Super Black Eagle 3 at 50 m4. Several firearms here have no recorded muzzle velocity figure, so the comparison is a description of the available entries rather than a complete ranking of all examples.
Muzzle velocity, compared
4 of the firearms named record no muzzle velocity.
The data in this chart
| Firearm | Muzzle velocity (m/s) |
|---|---|
| Mossberg 590A1 | 457 |
| Browning Auto-5 | 396 |
| Beretta 1301 Tactical | 381 |
| Beretta A300 Ultima Patrol | 381 |
Why the cartridge dimensions matter to the firearm list
The dimensions in the 12 Gauge record help explain why the firearm list is so broad. The catalogue describes a straight, rimmed case with a 70 mm1 overall length and a 22.5 mm rim diameter. Those figures recur across very different shotgun mechanisms and layouts, which matters because it shows one cartridge pattern carried forward through successive design eras rather than belonging to one narrow family of arms.
In the sample here, that same cartridge geometry appears in the long-recoil Browning Auto-5, introduced in 19022, and also in later gas-operated self-loaders such as the Beretta 1301 Tactical, introduced in 20143, and the Beretta A300 Ultima Patrol, introduced in 2023. Elsewhere in the same chambering set are pump-action, inertia-operated and bullpup designs. The point is not that these firearms are alike, but that the cartridge dimensions are stable enough to span markedly different operating systems and form factors.
That breadth is reflected in the catalogue total: 12 Gauge is chambered by 680 firearms. Within this database, that supports its place as one of the broadest and longest-lived cartridge records.
For the full cartridge entry, including dimensions and the current firearm list, see the 12 Gauge catalogue page.
Sources and methods
Figures under review. The catalogue's own data checks still question one figure in this post, given here as the record states it. How the data is checked.
| Task | Figure | Open question |
|---|---|---|
| View task | 12 Gauge maximum pressure | Its sources disagree |
Footnotes
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GunSpec catalogue record for the 12 Gauge, which cites theballisticassistant.com. In the API: calibers reference and ammunition reference. ↩ ↩2 ↩3 ↩4
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GunSpec catalogue record for the Browning Auto-5, which cites britannica.com, militaryfactory.com. In the API: firearms reference. ↩ ↩2 ↩3 ↩4
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GunSpec catalogue record for the Beretta 1301 Tactical, which cites beretta.com, en.wikipedia.org, shootingillustrated.com, luckygunner.com. In the API: firearms reference. ↩ ↩2 ↩3 ↩4
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GunSpec catalogue record for the Benelli M1014, which cites benelliusa.com, en.wikipedia.org. In the API: firearms reference. ↩ ↩2 ↩3
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Method, comparisons: a difference is one catalogue figure minus another of the same kind, in the same unit. Comparisons. ↩ ↩2
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GunSpec catalogue record for the IWI Tavor TS12, which cites en.wikipedia.org, iwi.us, iwi.us, americanrifleman.org. In the API: firearms reference. ↩
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GunSpec catalogue record for the Benelli Super Black Eagle 3, which cites benelliusa.com, americanhunter.org, fieldandstream.com, realtree.com. In the API: firearms reference. ↩
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GunSpec catalogue record for the Beretta A300 Ultima Patrol, which cites beretta.com, americanrifleman.org, shootingillustrated.com, recoilweb.com. In the API: firearms reference. ↩
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GunSpec catalogue record for the Mossberg 590A1, which cites mossberg.com, mossberg.com, en.wikipedia.org, shootingillustrated.com. In the API: firearms reference. ↩ ↩2
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GunSpec catalogue record for the Mossberg 940 Pro Tactical, which cites mossberg.com, mossberg.com, americanrifleman.org, recoilweb.com. In the API: firearms reference. ↩
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