The 38 Special is a centerfire handgun cartridge standardised by SAAMI in ANSI/SAAMI Z299.3. SAAMI sets its maximum average pressure at 17,000 psi, and publishes its reference velocities for both a vented barrel and the standard test barrel. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 38 Special with the 357 Magnum on the same basis.
38 Special ballistics chart: SAAMI reference data
SAAMI publishes nominal mean instrumental velocities for each reference bullet weight, measured at 15 feet from a vented barrel and from the standard test barrel, and marks a figure it has not established. It does not publish energy, so the ft-lb figures are 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 | Vented-barrel velocity / computed energy | Test-barrel velocity / computed energy |
|---|---|---|
| 90 gr | 950 fps / 180 ft-lb | 1,180 fps / 278 ft-lb |
| 100 gr | 950 fps / 200 ft-lb | Not established |
| 110 gr | 945–1,000 fps / 218–244 ft-lb | 975–1,150 fps / 232–323 ft-lb |
| 125 gr | Not established | 950–1,050 fps / 250–306 ft-lb |
| 130 gr | 775–895 fps / 173–231 ft-lb | 775–1,040 fps / 173–312 ft-lb |
| 148 gr | Not established | 800 fps / 210 ft-lb |
| 150 gr | Not established | 900 fps / 270 ft-lb |
| 158 gr | 750 fps / 197 ft-lb | 900 fps / 284 ft-lb |
| 200 gr | 630 fps / 176 ft-lb | 780 fps / 270 ft-lb |
What the numbers mean for a shot
SAAMI lists 9 reference bullet weights for the 38 Special, from 90 to 200 grains. The lightest, 90 grains, is listed at 950 fps in a vented barrel (180 ft-lb computed) and 1,180 fps in the test barrel (278 ft-lb computed). The heaviest, 200 grains, is listed at 630 fps in a vented barrel (176 ft-lb computed) and 780 fps in the test barrel (270 ft-lb computed). The most energetic reference load is the 110-grain at 1,150 fps in the test barrel: 323 ft-lb computed.
SAAMI lists more than one reference velocity for 110, 125 and 130 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 38 Special ammo range lists whatever its maker publishes for that item.
Barrel, chamber and pressure
A revolver loses some gas, and with it velocity, at the gap between cylinder and barrel, which is why SAAMI publishes a vented-barrel velocity for revolver cartridges beside the test-barrel one. SAAMI notes that the vented-barrel figures “are provided for information only” and that vented test barrels are used for the establishment of catalog velocity values for cartridges normally chambered in revolvers. Your own revolver’s barrel length will move the numbers again. The maximum average pressure is 17,000 psi. Fire 38 Special 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. SAAMI also standardises a +P level for the 38 Special, at 20,000 psi. +P ammunition is loaded to a higher pressure and should be fired only in a firearm its maker states is rated for it.
38 Special vs 357 Magnum: 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 | 38 Special | 357 Magnum |
|---|---|---|
| Maximum average pressure | 17,000 psi | 35,000 psi |
| Maximum average pressure, +P | 20,000 psi | No +P standard |
| Standard test barrel length | Revolver test barrel (see SAAMI drawing) | Revolver test barrel (see SAAMI drawing) |
| Test barrel twist rate | 1 turn in 18.75 in | 1 turn in 18.75 in |
| Test barrel groove diameter | .355 in | .355 in |
| Lightest reference load | 90 gr — 1,180 fps / 278 ft-lb | 101 gr — 1,650 fps / 610 ft-lb |
| A weight both list | 130 gr — 775–1,040 fps / 173–312 ft-lb | 130 gr — 1,475 fps / 628 ft-lb |
| Heaviest reference load | 200 gr — 780 fps / 270 ft-lb | 180 gr — 1,350–1,400 fps / 728–783 ft-lb |
SAAMI standardises the 38 Special at 17,000 psi and the 357 Magnum at 35,000 psi, so the 38 Special runs 18,000 psi lower. At 130 grains, a weight both list, SAAMI’s 38 Special reference velocity is up to 1,040 fps (312 ft-lb computed), against 1,475 fps (628 ft-lb) for the 357 Magnum. On that row the 357 Magnum carries the more energy.
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: 357 Magnum ammo.
38 Special ballistics questions
What is the maximum pressure of the 38 Special?
ANSI/SAAMI Z299.3 sets the maximum average pressure for the 38 Special at 17,000 psi.
What twist rate does SAAMI use for the 38 Special?
SAAMI’s test barrel drawing for the 38 Special shows rifling of 1 turn in 18.75 in. Revolver barrel lengths vary widely, so your own revolver may differ.
What bullet weights does SAAMI list for the 38 Special?
SAAMI lists 9 reference weights, from 90 to 200 grains: 90, 100, 110, 125, 130, 148, 150, 158 and 200.
Is the 38 Special more powerful than the 357 Magnum?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 130 grains, a weight both list, SAAMI’s 38 Special reference velocity is up to 1,040 fps (312 ft-lb computed), against 1,475 fps (628 ft-lb) for the 357 Magnum.
What is the +P pressure limit for the 38 Special?
SAAMI standardises a +P level for the 38 Special at 20,000 psi, against 17,000 psi for standard-pressure ammunition. +P ammunition should be fired only in a firearm its maker states is rated for it.
What is the effective range of the 38 Special?
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.
Where to buy these loads
Hilltop Armory carries 38 Special ammunition from Remington, Winchester, Federal, Hornady, Underwood and Magtech. Browse the full 38 Special ammo range.
