The 475 Linebaugh is a centerfire handgun cartridge standardised by SAAMI in ANSI/SAAMI Z299.3. SAAMI sets its maximum average pressure at 50,000 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 475 Linebaugh with the 480 Ruger on the same basis.
475 Linebaugh 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 |
|---|---|---|
| 400 gr | 1,300 fps / 1,501 ft-lb | 1,400 fps / 1,741 ft-lb |
What the numbers mean for a shot
SAAMI lists a single reference bullet weight for the 475 Linebaugh: 400 grains, listed at 1,300 fps in a vented barrel (1,501 ft-lb computed) and 1,400 fps in the test barrel (1,741 ft-lb computed). 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 475 Linebaugh 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 50,000 psi. Fire 475 Linebaugh 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.
475 Linebaugh vs 480 Ruger: 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 | 475 Linebaugh | 480 Ruger |
|---|---|---|
| Maximum average pressure | 50,000 psi | 48,000 psi |
| Standard test barrel length | Revolver test barrel (see SAAMI drawing) | Revolver test barrel (see SAAMI drawing) |
| Test barrel twist rate | 1 turn in 18.00 in | 1 turn in 18.00 in |
| Test barrel groove diameter | .475 in | .475 in |
| Lightest reference load | 400 gr — 1,400 fps / 1,741 ft-lb | 325 gr — 1,425 fps / 1,465 ft-lb |
SAAMI standardises the 475 Linebaugh at 50,000 psi and the 480 Ruger at 48,000 psi, so the 475 Linebaugh runs 2,000 psi higher. SAAMI lists no bullet weight in common for the two, so there is no like-for-like velocity row to compare.
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: 480 Ruger ammo.
475 Linebaugh ballistics questions
What is the maximum pressure of the 475 Linebaugh?
ANSI/SAAMI Z299.3 sets the maximum average pressure for the 475 Linebaugh at 50,000 psi.
What twist rate does SAAMI use for the 475 Linebaugh?
SAAMI’s test barrel drawing for the 475 Linebaugh shows rifling of 1 turn in 18.00 in. Revolver barrel lengths vary widely, so your own revolver may differ.
Is the 475 Linebaugh more powerful than the 480 Ruger?
SAAMI lists no bullet weight in common for the two, so there is no like-for-like row. Its highest computed reference energy is 1,741 ft-lb for the 475 Linebaugh (400 grains) and 1,465 ft-lb for the 480 Ruger.
What is the effective range of the 475 Linebaugh?
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 475 Linebaugh drop at 100 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 475 Linebaugh ammunition from Buffalo Bore, Grizzly Cartridge Company and Hornady. Browse the full 475 Linebaugh ammo range.
