The 380 Automatic is a centerfire handgun cartridge standardised by SAAMI in ANSI/SAAMI Z299.3. SAAMI sets its maximum average pressure at 21,500 psi, and measures its reference velocities in a 3.750 in standard test barrel rifled 1 turn in 16.00 in, left hand. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 380 Automatic with the 9mm Luger on the same basis.
380 ACP ballistics chart: SAAMI reference data
SAAMI publishes one nominal mean instrumental velocity for each reference bullet weight, measured at 15 feet from the standard test barrel. It does not publish energy, so the ft-lb column is computed. Where SAAMI lists more than one velocity for a weight, both ends of the span are shown.
Scroll the table sideways for the remaining columns.
| Bullet weight | Reference velocity | Computed muzzle energy |
|---|---|---|
| 65 gr | 1,050 fps | 159 ft-lb |
| 80 gr | 980–1,100 fps | 171–215 ft-lb |
| 85 gr | 990–1,060 fps | 185–212 ft-lb |
| 95 gr | 945–990 fps | 188–207 ft-lb |
| 99 gr | 1,030 fps | 233 ft-lb |
| 100 gr | 910 fps | 184 ft-lb |
What the numbers mean for a shot
SAAMI lists 6 reference bullet weights for the 380 Automatic, from 65 to 100 grains. The lightest, 65 grains, is listed at 1,050 fps, which computes to 159 ft-lb. The heaviest, 100 grains, is listed at 910 fps, which computes to 184 ft-lb. The most energetic reference load is the 99-grain at 1,030 fps: 233 ft-lb computed. The fastest is the 80-grain at 1,100 fps.
SAAMI lists more than one reference velocity for 80, 85 and 95 grains. Its own note says this is because a weight can carry several introductions meeting different market needs, such as reduced-recoil loads, or because propellant and loading advances allowed higher velocities after the original load appeared.
None of this is a downrange figure. SAAMI measures at 15 feet, so retained velocity, energy and drop depend on the bullet’s ballistic coefficient, which SAAMI does not publish. Each product in our 380 ACP ammo range lists whatever its maker publishes for that item.
Barrel, chamber and pressure
SAAMI’s standard test barrel for the 380 Automatic is 3.750 in long and rifled 1 turn in 16.00 in, left hand. That is the barrel every reference velocity above was measured in, not a statement about your handgun: handgun barrels vary widely in length, and a shorter barrel gives lower velocity. The maximum average pressure is 21,500 psi. Fire 380 Automatic ammunition only in a firearm chambered for it. Several unrelated cartridges share a number, so match the full designation on the box to the marking on your barrel.
380 ACP vs 9mm: 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, zero and bullet, and many publish no test barrel at all. SAAMI is the shared basis, because it fixes one standard test barrel and one way of measuring velocity for every cartridge it lists.
Scroll the table sideways for the remaining columns.
| SAAMI specification | 380 Automatic | 9mm Luger |
|---|---|---|
| Maximum average pressure | 21,500 psi | 35,000 psi |
| Maximum average pressure, +P | No +P standard | 38,500 psi |
| Standard test barrel length | 3.750 in | 4.000 in |
| Test barrel twist rate | 1 turn in 16.00 in, left hand | 1 turn in 10.00 in |
| Test barrel groove diameter | Not read from the drawing | .3550 in |
| Lightest reference load | 65 gr — 1,050 fps / 159 ft-lb | 88 gr — 1,500 fps / 440 ft-lb |
| A weight both list | 100 gr — 910 fps / 184 ft-lb | 100 gr — 1,110–1,195 fps / 274–317 ft-lb |
| Heaviest reference load | 100 gr — 910 fps / 184 ft-lb | 150 gr — 900 fps / 270 ft-lb |
SAAMI standardises the 380 Automatic at 21,500 psi and the 9mm Luger at 35,000 psi, so the 380 Automatic runs 13,500 psi lower. At 100 grains, a weight both list, SAAMI’s 380 Automatic reference velocity is 910 fps (184 ft-lb computed), against up to 1,195 fps (317 ft-lb) for the 9mm Luger. On that row the 9mm Luger carries the more energy. Their standard test barrels differ (3.750 in, 1 turn in 16.00 in, left hand for the 380 Automatic; 4.000 in, 1 turn in 10.00 in for the 9mm Luger), so compare the reference rows with that in mind.
What SAAMI cannot settle is anything past the muzzle. It publishes no ballistic coefficients and no downrange data, so it cannot say which cartridge shoots flatter at distance; that depends on the bullet. We stock the other side of this comparison too: 9mm ammo.
380 ACP ballistics questions
What is the maximum pressure of the 380 Automatic?
ANSI/SAAMI Z299.3 sets the maximum average pressure for the 380 Automatic at 21,500 psi.
What twist rate and barrel length does SAAMI use for the 380 Automatic?
SAAMI’s standard test barrel for the 380 Automatic is 3.750 in long and rifled 1 turn in 16.00 in, left hand. Your own handgun may differ.
What bullet weights does SAAMI list for the 380 Automatic?
SAAMI lists 6 reference weights, from 65 to 100 grains: 65, 80, 85, 95, 99 and 100.
Is the 380 Automatic more powerful than the 9mm Luger?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 100 grains, a weight both list, SAAMI’s 380 Automatic reference velocity is 910 fps (184 ft-lb computed), against up to 1,195 fps (317 ft-lb) for the 9mm Luger.
What is the effective range of the 380 Automatic?
Effective range is not a SAAMI specification and it is not a measured figure. SAAMI measures velocity at 15 feet, so it says nothing about performance at distance; that depends on the bullet and the shooter.
How much does the 380 Automatic drop at 100 yards?
SAAMI publishes muzzle velocity only, so it cannot give a drop figure. Drop depends on the bullet’s ballistic coefficient and on the zero range. A drop figure is unusable without its zero, so use the figure a maker prints for the specific load.
Where to buy these loads
Hilltop Armory carries 380 ACP ammunition from Underwood, Buffalo Bore, Federal, Winchester, AMMO, Inc. and Remington. Browse the full 380 ACP ammo range.
