The 277 SIG Fury is a centerfire rifle cartridge standardised by SAAMI in ANSI/SAAMI Z299.4. SAAMI sets its maximum average pressure at 80,000 psi, and measures its reference velocities in a 16.000 in 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 277 SIG Fury with the 270 Winchester on the same basis.
277 Sig Fury 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 | 3,000 fps | 2,697 ft-lb |
What the numbers mean for a shot
SAAMI lists a single reference bullet weight for the 277 SIG Fury: 135 grains, listed at 3,000 fps, which computes to 2,697 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 277 Sig Fury ammo range lists whatever its maker publishes for that item.
Twist rate, chamber and pressure
SAAMI measures the 277 SIG Fury in a 16.000 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 80,000 psi. Fire 277 SIG Fury 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 warns that maximum average pressures above 65,000 psi may present increased risk of unsafe cartridge case or firearm rupture, and require case and firearm designs that depart from traditional practice.
277 Sig Fury vs 270: 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 | 277 SIG Fury | 270 Winchester |
|---|---|---|
| Maximum average pressure | 80,000 psi | 65,000 psi |
| Standard test barrel length | 16.000 in | 24.000 in |
| Test barrel twist rate | Not read from the drawing | 1 turn in 10.00 in |
| Test barrel groove diameter | .277 in | .277 in |
| Lightest reference load | 135 gr — 3,000 fps / 2,697 ft-lb | 100 gr — 3,300 fps / 2,418 ft-lb |
| A weight both list | 135 gr — 3,000 fps / 2,697 ft-lb | 135 gr — 2,990 fps / 2,679 ft-lb |
| Heaviest reference load | 135 gr — 3,000 fps / 2,697 ft-lb | 160 gr — 2,650 fps / 2,494 ft-lb |
SAAMI standardises the 277 SIG Fury at 80,000 psi and the 270 Winchester at 65,000 psi, so the 277 SIG Fury runs 15,000 psi higher. At 135 grains, a weight both list, SAAMI’s 277 SIG Fury reference velocity is 3,000 fps (2,697 ft-lb computed), against 2,990 fps (2,679 ft-lb) for the 270 Winchester. On that row the 277 SIG Fury carries the more energy. Their standard test barrels differ (16.000 in, twist not read for the 277 SIG Fury; 24.000 in, 1 turn in 10.00 in for the 270 Winchester), 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: 270 ammo.
277 Sig Fury ballistics questions
What is the maximum pressure of the 277 SIG Fury?
ANSI/SAAMI Z299.4 sets the maximum average pressure for the 277 SIG Fury at 80,000 psi.
Is the 277 SIG Fury more powerful than the 270 Winchester?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 135 grains, a weight both list, SAAMI’s 277 SIG Fury reference velocity is 3,000 fps (2,697 ft-lb computed), against 2,990 fps (2,679 ft-lb) for the 270 Winchester.
What is the effective range of the 277 SIG Fury?
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 277 SIG Fury 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 277 Sig Fury ammunition from SIG SAUER. Browse the full 277 Sig Fury ammo range.
