The 375 Remington Ultra 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 12.00 in. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 375 Remington Ultra Magnum with the 375 Holland & Holland Magnum on the same basis.
375 RUM 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 |
|---|---|---|
| 270 gr | 2,900–2,975 fps | 5,041–5,305 ft-lb |
| 300 gr | 2,750 fps | 5,037 ft-lb |
What the numbers mean for a shot
SAAMI lists two reference bullet weights for the 375 Remington Ultra Magnum, 270 and 300 grains. The lighter, 270 grains, is listed at 2,900–2,975 fps, which computes to 5,041–5,305 ft-lb. The heavier, 300 grains, is listed at 2,750 fps, which computes to 5,037 ft-lb.
SAAMI lists more than one reference velocity for 270 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 375 RUM ammo range lists whatever its maker publishes for that item.
Twist rate, chamber and pressure
SAAMI’s standard test barrel for the 375 Remington Ultra Magnum is 24.000 in long and rifled 1 turn in 12.00 in, with a .376 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 375 Remington Ultra 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.
375 RUM vs 375 H&H 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 | 375 Remington Ultra Magnum | 375 Holland & Holland Magnum |
|---|---|---|
| Maximum average pressure | 65,000 psi | 62,000 psi |
| Standard test barrel length | 24.000 in | 24.000 in |
| Test barrel twist rate | 1 turn in 12.00 in | 1 turn in 12.00 in |
| Test barrel groove diameter | .376 in | .376 in |
| Lightest reference load | 270 gr — 2,900–2,975 fps / 5,041–5,305 ft-lb | 250 gr — 2,670–2,890 fps / 3,957–4,636 ft-lb |
| A weight both list | 300 gr — 2,750 fps / 5,037 ft-lb | 300 gr — 2,400–2,680 fps / 3,836–4,784 ft-lb |
SAAMI standardises the 375 Remington Ultra Magnum at 65,000 psi and the 375 Holland & Holland Magnum at 62,000 psi, so the 375 Remington Ultra Magnum runs 3,000 psi higher. At 300 grains, a weight both list, SAAMI’s 375 Remington Ultra Magnum reference velocity is 2,750 fps (5,037 ft-lb computed), against up to 2,680 fps (4,784 ft-lb) for the 375 Holland & Holland Magnum. On that row the 375 Remington Ultra 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: 375 H&H Magnum ammo.
375 RUM ballistics questions
What is the maximum pressure of the 375 Remington Ultra Magnum?
ANSI/SAAMI Z299.4 sets the maximum average pressure for the 375 Remington Ultra Magnum at 65,000 psi.
What twist rate and barrel length does SAAMI use for the 375 Remington Ultra Magnum?
SAAMI’s standard test barrel for the 375 Remington Ultra Magnum is 24.000 in long and rifled 1 turn in 12.00 in. Your own rifle may differ.
What bullet weights does SAAMI list for the 375 Remington Ultra Magnum?
SAAMI lists 2 reference weights, from 270 to 300 grains: 270 and 300.
Is the 375 Remington Ultra Magnum more powerful than the 375 Holland & Holland Magnum?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 300 grains, a weight both list, SAAMI’s 375 Remington Ultra Magnum reference velocity is 2,750 fps (5,037 ft-lb computed), against up to 2,680 fps (4,784 ft-lb) for the 375 Holland & Holland Magnum.
What is the effective range of the 375 Remington Ultra 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.
How much does the 375 Remington Ultra 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.
Where to buy these loads
Hilltop Armory carries 375 RUM ammunition from Nosler, CorBon and DoubleTap Ammunition. Browse the full 375 RUM ammo range.
