The 28 Gauge is a shotshell standardised by SAAMI in ANSI/SAAMI Z299.2, which lists it in the 2 3/4 inch shell at a maximum average pressure of 12,500 psi. This guide sets out SAAMI’s published reference velocity for each shot weight in each shell length, for lead and non-lead shot, and compares the 28 Gauge with the 20 Gauge on the same basis.
28 Gauge ballistics chart: SAAMI reference data
SAAMI lists shotshell reference loads by shot weight within each shell length, and publishes a nominal mean instrumental velocity for each, measured at 3 feet from the standard test barrel. Rifle and handgun cartridges are measured at 15 feet, so a shotshell velocity is not measured on the same basis as theirs. SAAMI lists lead shot and non-lead shot loads separately and fires them in test barrels with different chokes, so the tables give them in separate columns. SAAMI publishes no energy for shot loads, so no energy is shown.
28 Gauge, 2 3/4 inch shell
Scroll the table sideways for the remaining columns.
| Shot weight | Lead shot: velocity at 3 ft | Non-lead shot: velocity at 3 ft |
|---|---|---|
| 5/8 oz | 1,160 fps | 1,300; 1,350 fps |
| 3/4 oz | 1,200; 1,295 fps | Not listed |
| 7/8 oz | 1,250 fps | Not listed |
| 1 oz | 1,205 fps | Not listed |
What the numbers mean for a shot
SAAMI lists one shell length for the 28 Gauge: 2 3/4 inch. Its lead shot loads carry from 5/8 oz to 1 oz of shot and its non-lead shot loads carry 5/8 oz. At 3 feet, SAAMI’s lead shot reference velocities are from 1,160 to 1,295 fps, and its non-lead shot reference velocities are from 1,300 to 1,350 fps.
SAAMI lists no slug or buckshot loads for the 28 Gauge.
None of this is a pattern, range or energy figure. SAAMI’s shotshell tables give shot weight rather than shot size or pellet count, measure velocity at 3 feet, and publish no pattern or energy data, so they cannot say how far a load is effective or how hard it hits. Each product in our 28 Gauge ammo range lists whatever its maker publishes for that item.
Shell length, chamber and pressure
The maximum average pressure for the 28 Gauge is 12,500 psi. Never fire a shell longer than the chamber of your shotgun. Check the chamber length marked on the barrel or given in the owner’s manual, and match the gauge and shell length printed on the box to it.
SAAMI’s lead shot reference velocities were measured in test barrels with a choke constriction of .031 ± .005 in (0.79 mm ± 0.13 mm), and its non-lead shot velocities in test barrels with .005 ± .005 in (0.13 mm ± 0.13 mm). Those are the barrels every velocity above was measured in, not a statement about your shotgun: your own barrel and choke can give different figures. Check the barrel and choke maker’s instructions before firing non-lead shot, and check the current regulations where you hunt, because rules on which shot may be used, for waterfowl in particular, vary by location.
28 Gauge vs 20 Gauge: the SAAMI comparison
A figure from one maker’s catalogue cannot be laid beside a figure from another’s: each picks its own test barrel, choke and payload. SAAMI is the shared basis, because it fixes one standard test barrel and one way of measuring velocity for every shotshell it lists.
Scroll the table sideways for the remaining columns.
| SAAMI specification | 28 Gauge | 20 Gauge |
|---|---|---|
| Shell lengths SAAMI lists | 2 3/4 inch | 2 3/4 and 3 inch |
| Maximum average pressure, 2 3/4 inch shell | 12,500 psi | 12,000 psi |
| Maximum average pressure, 3 inch shell | Not listed | 12,000 psi |
| Lead shot, 2 3/4 inch shell | 5/8 oz to 1 oz; 1,160–1,295 fps | 3/4 oz to 1 1/8 oz; 980–1,390 fps |
| Non-lead shot, 2 3/4 inch shell | 5/8 oz; 1,300–1,350 fps | 3/4 oz to 1 1/8 oz; 1,100–1,425 fps |
| Rifled slug, 2 3/4 inch shell | Not listed | 1/2 oz to 7/8 oz; 1,540–1,810 fps |
| Saboted slug, 2 3/4 inch shell | Not listed | 250 gr to 1 oz; 1,270–1,900 fps |
| Lead buckshot, 2 3/4 inch shell | Not listed | 3 buck; 1,200 fps |
In the 2 3/4 inch shell, SAAMI standardises the 28 Gauge at 12,500 psi and the 20 Gauge at 12,000 psi, so the 28 Gauge runs 500 psi higher. The heaviest lead shot load SAAMI lists in that shell is 1 oz for the 28 Gauge and 1 1/8 oz for the 20 Gauge. A higher pressure limit is a ceiling on the load, not a measure of its power.
What SAAMI cannot settle is anything past the muzzle. It publishes no pattern, shot size or downrange data, so it cannot say which gauge is more effective at a given distance; that depends on the load and the choke. We stock the other side of this comparison too: 20 Gauge ammo.
28 Gauge ballistics questions
What is the maximum pressure of the 28 Gauge?
ANSI/SAAMI Z299.2 sets the maximum average pressure for the 28 Gauge at 12,500 psi.
How fast is a 28 Gauge shotshell?
SAAMI’s reference velocities for the 28 Gauge, measured at 3 feet from the standard test barrel, are from 1,160 to 1,295 fps for lead shot and from 1,300 to 1,350 fps for non-lead shot.
Is the 28 Gauge more powerful than the 20 Gauge?
Power is not a SAAMI measure. What SAAMI publishes is a maximum average pressure and the shot weights and velocities of its reference loads. In the 2 3/4 inch shell, which both list, the heaviest lead shot load SAAMI lists is 1 oz for the 28 Gauge and 1 1/8 oz for the 20 Gauge, at maximum average pressures of 12,500 psi and 12,000 psi.
What shot weights does SAAMI list for the 28 Gauge?
SAAMI lists lead shot loads carrying from 5/8 oz to 1 oz and non-lead shot loads carrying 5/8 oz.
What is the effective range of a 28 Gauge?
Effective range is not a SAAMI specification. SAAMI measures velocity at 3 feet and publishes no pattern or energy data, so it says nothing about performance at distance; that depends on the load, the shot size and the choke.
Where to buy these loads
Hilltop Armory carries 28 Gauge ammunition from Federal, Winchester, HEVI-Shot, Fiocchi, Apex Ammunition and Baschieri & Pellagri. Browse the full 28 Gauge ammo range.
