The 325 Winchester Short Magnum is a centerfire rifle cartridge standardised by SAAMI in ANSI/SAAMI Z299.4. SAAMI sets its maximum average pressure at 65,000 psi, and measures its reference velocities in a 24.000 in standard test barrel rifled 1 turn in 10.00 in. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 325 Winchester Short Magnum with the 300 Winchester Short Magnum on the same basis.
325 WSM 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 |
|---|---|---|
| 180 gr | 3,050 fps | 3,717 ft-lb |
| 200 gr | 2,940 fps | 3,838 ft-lb |
| 220 gr | 2,830 fps | 3,912 ft-lb |
What the numbers mean for a shot
SAAMI lists 3 reference bullet weights for the 325 Winchester Short Magnum, from 180 to 220 grains. The lightest, 180 grains, is listed at 3,050 fps, which computes to 3,717 ft-lb. The heaviest, 220 grains, is listed at 2,830 fps, or 3,912 ft-lb.
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 325 WSM ammo range lists whatever its maker publishes for that item.
Twist rate, chamber and pressure
SAAMI’s standard test barrel for the 325 Winchester Short Magnum is 24.000 in long and rifled 1 turn in 10.00 in, with a .323 in groove diameter. That is the barrel every reference velocity above was measured in, not a statement about your rifle: a shorter production barrel will usually give lower velocity, and a twist slower than a bullet needs will not stabilise it. The maximum average pressure is 65,000 psi. Fire 325 Winchester Short Magnum 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.
325 WSM vs 300 WSM: 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 | 325 Winchester Short Magnum | 300 Winchester Short Magnum |
|---|---|---|
| Maximum average pressure | 65,000 psi | 65,000 psi |
| Standard test barrel length | 24.000 in | Not read from the drawing |
| Test barrel twist rate | 1 turn in 10.00 in | 1 turn in 10.00 in |
| Test barrel groove diameter | .323 in | .308 in |
| Lightest reference load | 180 gr — 3,050 fps / 3,717 ft-lb | 150 gr — 3,300 fps / 3,626 ft-lb |
| A weight both list | 200 gr — 2,940 fps / 3,838 ft-lb | 200 gr — 2,810 fps / 3,506 ft-lb |
| Heaviest reference load | 220 gr — 2,830 fps / 3,912 ft-lb | 200 gr — 2,810 fps / 3,506 ft-lb |
The 325 Winchester Short Magnum and the 300 Winchester Short Magnum share the same maximum average pressure, 65,000 psi. At 200 grains, a weight both list, SAAMI’s 325 Winchester Short Magnum reference load is 2,940 fps and 3,838 ft-lb computed, against 2,810 fps and 3,506 ft-lb for the 300 Winchester Short Magnum. On that row the 325 Winchester Short Magnum carries the more energy. Their standard test barrels differ (24.000 in, 1 turn in 10.00 in for the 325 Winchester Short Magnum; length not read, 1 turn in 10.00 in for the 300 Winchester Short Magnum), 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: 300 WSM ammo.
325 WSM ballistics questions
What is the maximum pressure of the 325 Winchester Short Magnum?
ANSI/SAAMI Z299.4 sets the maximum average pressure for the 325 Winchester Short Magnum at 65,000 psi.
What twist rate and barrel length does SAAMI use for the 325 Winchester Short Magnum?
SAAMI’s standard test barrel for the 325 Winchester Short Magnum is 24.000 in long and rifled 1 turn in 10.00 in. Your own rifle may differ, and a twist slower than a long, heavy bullet needs will not stabilise it.
What bullet weights does SAAMI list for the 325 Winchester Short Magnum?
SAAMI lists 3 reference weights, from 180 to 220 grains: 180, 200 and 220.
Is the 325 Winchester Short Magnum more powerful than the 300 Winchester Short Magnum?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 200 grains, a weight both list, SAAMI’s 325 Winchester Short Magnum reference load is 2,940 fps and 3,838 ft-lb computed, against 2,810 fps and 3,506 ft-lb for the 300 Winchester Short Magnum.
How much does the 325 Winchester Short Magnum drop at 300 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.
What is the effective range of the 325 Winchester Short Magnum?
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 325 WSM ammunition from Nosler, DoubleTap Ammunition and Winchester. Browse the full 325 WSM ammo range.
