The 348 Winchester 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 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 348 Winchester with the 45-70 Government on the same basis.
348 Winchester 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 |
|---|---|---|
| 200 gr | 2,505 fps | 2,786 ft-lb |
What the numbers mean for a shot
SAAMI lists a single reference bullet weight for the 348 Winchester: 200 grains, listed at 2,505 fps, which computes to 2,786 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 348 Winchester ammo range lists whatever its maker publishes for that item.
Twist rate, chamber and pressure
SAAMI’s standard test barrel for the 348 Winchester is 24.000 in long and rifled 1 turn in 12.00 in, with a .348 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 45,000 psi. Fire 348 Winchester 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.
348 Winchester vs 45-70: 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 | 348 Winchester | 45-70 Government |
|---|---|---|
| Maximum average pressure | 45,000 psi | 28,000 psi |
| Standard test barrel length | 24.000 in | 24.000 in |
| Test barrel twist rate | 1 turn in 12.00 in | 1 turn in 20.00 in |
| Test barrel groove diameter | .348 in | .456 in |
| Lightest reference load | 200 gr — 2,505 fps / 2,786 ft-lb | 250 gr — 2,025 fps / 2,276 ft-lb |
| Heaviest reference load | 200 gr — 2,505 fps / 2,786 ft-lb | 405 gr — 1,150–1,600 fps / 1,189–2,302 ft-lb |
SAAMI standardises the 348 Winchester at 45,000 psi and the 45-70 Government at 28,000 psi, so the 348 Winchester runs 17,000 psi higher. 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 (24.000 in, 1 turn in 12.00 in for the 348 Winchester; 24.000 in, 1 turn in 20.00 in for the 45-70 Government), 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: 45-70 ammo.
348 Winchester ballistics questions
What is the maximum pressure of the 348 Winchester?
ANSI/SAAMI Z299.4 sets the maximum average pressure for the 348 Winchester at 45,000 psi.
What twist rate and barrel length does SAAMI use for the 348 Winchester?
SAAMI’s standard test barrel for the 348 Winchester is 24.000 in long and rifled 1 turn in 12.00 in. Your own rifle may differ.
Is the 348 Winchester more powerful than the 45-70 Government?
SAAMI lists no bullet weight in common for the two, so there is no like-for-like row. Its highest computed reference energy is 2,786 ft-lb for the 348 Winchester (200 grains) and 2,973 ft-lb for the 45-70 Government.
What is the effective range of the 348 Winchester?
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 348 Winchester 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 348 Winchester ammunition from Grizzly Cartridge Company, Buffalo Bore and Jamison Brass and Ammunition. Browse the full 348 Winchester ammo range.
