The 22 Winchester Rimfire is a rimfire cartridge standardised by SAAMI in ANSI/SAAMI Z299.1. SAAMI sets its maximum average pressure at 20,000 psi, and measures its reference velocities in a 24.000 in standard test barrel rifled 1 turn in 14 in. This guide sets out SAAMI’s published reference velocity for each bullet weight, computes the muzzle energy each one carries, and compares the 22 Winchester Rimfire with the 22 Winchester Magnum Rimfire on the same basis.
22 WRF ballistics chart: SAAMI reference data
SAAMI lists rimfire reference loads by bullet weight and by bullet type, and publishes a nominal mean instrumental velocity for each, measured at 15 feet from the standard test barrel. Bullet types are shown as the code SAAMI prints. It does not publish energy, so the ft-lb column is computed.
Scroll the table sideways for the remaining columns.
| Bullet weight | Bullet type (SAAMI code) | Reference velocity | Computed muzzle energy |
|---|---|---|---|
| 45 gr | JHP | 1,300 fps | 169 ft-lb |
What the numbers mean for a shot
SAAMI lists a single reference bullet weight for the 22 Winchester Rimfire: 45 grains, listed at 1,300 fps, which computes to 169 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 22 WRF ammo range lists whatever its maker publishes for that item.
Barrel, chamber and pressure
SAAMI’s standard test barrel for the 22 Winchester Rimfire is 24.000 in long and rifled 1 turn in 14 in, with a .226 in groove diameter. That is the barrel every reference velocity above was measured in, not a statement about your firearm: rimfire barrels vary widely in length, and a shorter barrel gives lower velocity. The maximum average pressure is 20,000 psi. Fire 22 Winchester Rimfire 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.
22 WRF vs 22 WMR: 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 | 22 Winchester Rimfire | 22 Winchester Magnum Rimfire |
|---|---|---|
| Maximum average pressure | 20,000 psi | 24,000 psi |
| Standard test barrel length | 24.000 in | 24.000 in |
| Test barrel twist rate | 1 turn in 14 in | 1 turn in 16 in |
| Test barrel groove diameter | .226 in | .224 in |
| Lightest reference load | 45 gr — 1,300 fps / 169 ft-lb | 28 gr — 2,175 fps / 294 ft-lb |
| A weight both list | 45 gr — 1,300 fps / 169 ft-lb | 45 gr — 1,550 fps / 240 ft-lb |
| Heaviest reference load | 45 gr — 1,300 fps / 169 ft-lb | 50 gr — 1,650 fps / 302 ft-lb |
SAAMI standardises the 22 Winchester Rimfire at 20,000 psi and the 22 Winchester Magnum Rimfire at 24,000 psi, so the 22 Winchester Rimfire runs 4,000 psi lower. At 45 grains, a weight both list, SAAMI’s 22 Winchester Rimfire reference velocity is 1,300 fps (169 ft-lb computed), against 1,550 fps (240 ft-lb) for the 22 Winchester Magnum Rimfire. On that row the 22 Winchester Magnum Rimfire carries the more energy. Their standard test barrels differ (24.000 in, 1 turn in 14 in for the 22 Winchester Rimfire; 24.000 in, 1 turn in 16 in for the 22 Winchester Magnum Rimfire), 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: 22 WMR ammo.
22 WRF ballistics questions
What is the maximum pressure of the 22 Winchester Rimfire?
ANSI/SAAMI Z299.1 sets the maximum average pressure for the 22 Winchester Rimfire at 20,000 psi.
What twist rate and barrel length does SAAMI use for the 22 Winchester Rimfire?
SAAMI’s standard test barrel for the 22 Winchester Rimfire is 24.000 in long and rifled 1 turn in 14 in. Your own firearm may differ.
Is the 22 Winchester Rimfire more powerful than the 22 Winchester Magnum Rimfire?
Power is not a SAAMI measure, but reference muzzle energy is a fair proxy. At 45 grains, a weight both list, SAAMI’s 22 Winchester Rimfire reference velocity is 1,300 fps (169 ft-lb computed), against 1,550 fps (240 ft-lb) for the 22 Winchester Magnum Rimfire.
What is the effective range of the 22 Winchester Rimfire?
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 22 Winchester Rimfire 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 22 WRF ammunition from CCI and Winchester. Browse the full 22 WRF ammo range.
