The 400 Legend is a centerfire rifle cartridge standardised by SAAMI in ANSI/SAAMI Z299.4. SAAMI sets its maximum average pressure at 45,000 psi, and measures its reference velocities in a 20.000 in standard test barrel rifled 1 turn in 16.00 in. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 400 Legend with the 350 Legend on the same basis.
400 Legend 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 |
|---|---|---|
| 215 gr | 2,230 fps | 2,374 ft-lb |
What the numbers mean for a shot
SAAMI lists a single reference bullet weight for the 400 Legend: 215 grains, listed at 2,230 fps, which computes to 2,374 ft-lb. SAAMI publishes no other weight for it, so the table has one row. For any other bullet weight, use the figures the maker publishes for that item.
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 400 Legend ammo range lists whatever its maker publishes for that item.
Twist rate, chamber and pressure
SAAMI’s standard test barrel for the 400 Legend is 20.000 in long and rifled 1 turn in 16.00 in, with a .4005 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. SAAMI measures the 400 Legend in a 20.000 in test barrel, not the 24.000 in used for most rifle cartridges, so its reference velocities cannot be set beside theirs without allowing for the barrel. The maximum average pressure is 45,000 psi. Fire 400 Legend 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.
400 Legend vs 350 Legend: 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 | 400 Legend | 350 Legend |
|---|---|---|
| Maximum average pressure | 45,000 psi | 55,000 psi |
| Standard test barrel length | 20.000 in | 16.000 in |
| Test barrel twist rate | 1 turn in 16.00 in | 1 turn in 16.00 in |
| Test barrel groove diameter | .4005 in | .355 in |
| Lightest reference load | 215 gr — 2,230 fps / 2,374 ft-lb | 124 gr — 2,470 fps / 1,680 ft-lb |
| Heaviest reference load | 215 gr — 2,230 fps / 2,374 ft-lb | 255 gr — 1,020 fps / 589 ft-lb |
SAAMI standardises the 400 Legend at 45,000 psi and the 350 Legend at 55,000 psi, so the 400 Legend runs 10,000 psi lower. SAAMI lists no bullet weight in common for the two, so there is no like-for-like velocity row to compare. Their standard test barrels differ (20.000 in, 1 turn in 16.00 in for the 400 Legend; 16.000 in, 1 turn in 16.00 in for the 350 Legend), 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: 350 Legend ammo.
400 Legend ballistics questions
What is the maximum pressure of the 400 Legend?
ANSI/SAAMI Z299.4 sets the maximum average pressure for the 400 Legend at 45,000 psi.
What twist rate and barrel length does SAAMI use for the 400 Legend?
SAAMI’s standard test barrel for the 400 Legend is 20.000 in long and rifled 1 turn in 16.00 in. Your own rifle may differ.
Is the 400 Legend more powerful than the 350 Legend?
SAAMI lists no bullet weight in common for the two, so there is no like-for-like row. Its highest computed reference energy is 2,374 ft-lb for the 400 Legend (215 grains) and 1,680 ft-lb for the 350 Legend.
What is the effective range of the 400 Legend?
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 400 Legend 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.
Where to buy these loads
Hilltop Armory carries 400 Legend ammunition from Winchester and Hornady. Browse the full 400 Legend ammo range.
