The 10mm Automatic is a centerfire handgun cartridge standardised by SAAMI in ANSI/SAAMI Z299.3. SAAMI sets its maximum average pressure at 37,500 psi, and measures its reference velocities in a 5.000 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 10mm Automatic with the 40 Smith & Wesson on the same basis.
10mm 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 |
|---|---|---|
| 135 gr | 1,310 fps | 514 ft-lb |
| 155 gr | 1,080–1,410 fps | 401–684 ft-lb |
| 170 gr | 1,320 fps | 658 ft-lb |
| 175 gr | 1,150–1,275 fps | 514–632 ft-lb |
| 180 gr | 1,030 fps | 424 ft-lb |
| 200 gr | 985–1,150 fps | 431–587 ft-lb |
What the numbers mean for a shot
SAAMI lists 6 reference bullet weights for the 10mm Automatic, from 135 to 200 grains. The lightest, 135 grains, is listed at 1,310 fps, which computes to 514 ft-lb. The heaviest, 200 grains, is listed at 985–1,150 fps, which computes to 431–587 ft-lb. The most energetic reference load is the 155-grain at 1,410 fps: 684 ft-lb computed.
SAAMI lists more than one reference velocity for 155, 175 and 200 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 10mm ammo range lists whatever its maker publishes for that item.
Barrel, chamber and pressure
SAAMI’s standard test barrel for the 10mm Automatic is 5.000 in long and rifled 1 turn in 16.00 in, left hand, with a .4005 in groove diameter. 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 37,500 psi. Fire 10mm 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.
10mm vs 40 S&W: 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 | 10mm Automatic | 40 Smith & Wesson |
|---|---|---|
| Maximum average pressure | 37,500 psi | 35,000 psi |
| Standard test barrel length | 5.000 in | 4.000 in |
| Test barrel twist rate | 1 turn in 16.00 in, left hand | 1 turn in 16.00 in |
| Test barrel groove diameter | .4005 in | .4005 in |
| Lightest reference load | 135 gr — 1,310 fps / 514 ft-lb | 125 gr — 1,300 fps / 469 ft-lb |
| A weight both list | 155 gr — 1,080–1,410 fps / 401–684 ft-lb | 155 gr — 1,115–1,195 fps / 428–491 ft-lb |
| Heaviest reference load | 200 gr — 985–1,150 fps / 431–587 ft-lb | 205 gr — 830 fps / 314 ft-lb |
SAAMI standardises the 10mm Automatic at 37,500 psi and the 40 Smith & Wesson at 35,000 psi, so the 10mm Automatic runs 2,500 psi higher. At 155 grains, a weight both list, SAAMI’s 10mm Automatic reference velocity is up to 1,410 fps (684 ft-lb computed), against up to 1,195 fps (491 ft-lb) for the 40 Smith & Wesson. On that row the 10mm Automatic carries the more energy. Their standard test barrels differ (5.000 in, 1 turn in 16.00 in, left hand for the 10mm Automatic; 4.000 in, 1 turn in 16.00 in for the 40 Smith & Wesson), 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: 40 S&W ammo.
10mm ballistics questions
What is the maximum pressure of the 10mm Automatic?
ANSI/SAAMI Z299.3 sets the maximum average pressure for the 10mm Automatic at 37,500 psi.
What twist rate and barrel length does SAAMI use for the 10mm Automatic?
SAAMI’s standard test barrel for the 10mm Automatic is 5.000 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 10mm Automatic?
SAAMI lists 6 reference weights, from 135 to 200 grains: 135, 155, 170, 175, 180 and 200.
Is the 10mm Automatic more powerful than the 40 Smith & Wesson?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 155 grains, a weight both list, SAAMI’s 10mm Automatic reference velocity is up to 1,410 fps (684 ft-lb computed), against up to 1,195 fps (491 ft-lb) for the 40 Smith & Wesson.
What is the effective range of the 10mm 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 10mm 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 10mm ammunition from Underwood, Buffalo Bore, Federal, Sellier And Bellot and SIG SAUER. Browse the full 10mm ammo range.
