What Is .22 WMRF

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Last updated: April 10, 2026

Quick Answer: The .22 Winchester Magnum Rimfire (.22 WMR) is a rimfire cartridge introduced in 1959 that delivers significantly higher velocity and power than the .22 Long Rifle, with muzzle energies of 300-340 foot-pounds compared to the LR's 100-140 foot-pounds. It achieves muzzle velocities of 1,900-2,400 feet per second and is widely used for hunting small game, varmint control, and target shooting.

Key Facts

Introduced in 1959 by Winchester; became one of the most popular rimfire hunting cartridges in North America
Generates 2-3 times more muzzle energy (300-340 ft-lbs) than .22 Long Rifle ammunition
Produces muzzle velocities of 1,900-2,400 feet per second with standard factory loads
Effective hunting range of 75-125 yards for small game like rabbits, squirrels, groundhogs, and prairie dogs
Available in rifles and handguns from manufacturers including Winchester, Ruger, CZ, and numerous other platforms

Overview

The .22 Winchester Magnum Rimfire (.22 WMR) is a rimfire cartridge that represents a significant step up in power and performance from the standard .22 Long Rifle. Introduced by Winchester in 1959, the .22 WMR was designed to deliver superior ballistics while maintaining the simplicity and economy of rimfire ammunition. The cartridge has become one of the most popular choices for hunters and shooters seeking more effective small-game hunting and varmint control capabilities.

The .22 WMR fires a .224-inch diameter projectile that typically weighs between 35 and 40 grains, achieving muzzle velocities of 1,900 to 2,400 feet per second depending on ammunition specifications. This results in muzzle energies ranging from 300 to 340 foot-pounds, substantially greater than the .22 LR's typical 100 to 140 foot-pounds. The increased power translates to flatter trajectory, better penetration, and improved terminal ballistics, making the .22 WMR considerably more effective for hunting applications beyond the range of its rimfire predecessor.

How It Works

The .22 WMR operates on the same fundamental principles as other rimfire cartridges, with the firing pin striking the primed rim of the cartridge case to initiate ignition. However, several design features distinguish the .22 WMR and contribute to its superior performance characteristics.

Cartridge Design: The .22 WMR uses a longer, heavier cartridge case than the .22 LR, typically 40mm in length, allowing it to contain more powder and produce higher velocities.
Primer System: The cartridge employs a more robust primer composition formulated to withstand and ignite the increased powder charge reliably across various environmental conditions.
Bullet Configuration: Factory ammunition uses heavier, optimized bullets designed specifically for the higher velocity ranges that the .22 WMR cartridge produces.
Velocity Performance: The combination of case capacity, powder charge, and bullet weight creates muzzle velocities ranging from 1,900 feet per second with subsonic loads to 2,400 feet per second with hypervelocity variants.
Accuracy Characteristics: The higher velocity and relatively flat trajectory provide inherent accuracy advantages, with the cartridge demonstrating excellent performance at extended ranges compared to standard rimfire options.

Key Comparisons

To understand the .22 WMR's position in the rimfire marketplace, comparison with other popular cartridges reveals its unique advantages and limitations.

Cartridge	Muzzle Velocity (fps)	Muzzle Energy (ft-lbs)	Effective Range
.22 Long Rifle	1,000–1,500	100–140	40–60 yards
.22 Winchester Magnum Rimfire	1,900–2,400	300–340	75–125 yards
.17 HMR	2,500–2,650	170–220	100–150 yards
.22 Hornet (centerfire)	2,200–2,600	500–700	150–200 yards

Why It Matters

The .22 WMR holds important significance in the hunting and shooting community for several compelling reasons that have sustained its popularity for over six decades.

Hunting Effectiveness: The cartridge provides sufficient power and range to ethically harvest small game including rabbits, squirrels, groundhogs, and varmints that exceed the effective range of .22 LR ammunition.
Platform Availability: Manufacturers produce numerous rifle and handgun options in .22 WMR, including lever-actions, semi-automatics, bolt-actions, and revolver configurations.
Cost Efficiency: As a rimfire cartridge, .22 WMR ammunition remains significantly more affordable than centerfire alternatives, making it economical for practice and hunting use.
Ballistic Advantage: The flatter trajectory and higher velocity compared to .22 LR reduce compensation requirements for wind and distance, improving first-round hit probability.
Reduced Recoil: The cartridge generates minimal recoil compared to centerfire options, benefiting younger shooters and those sensitive to recoil impulse.

The .22 Winchester Magnum Rimfire continues to represent an excellent balance between performance, affordability, and practicality. Its proven track record since 1959 demonstrates the cartridge's enduring value to hunters, pest controllers, and recreational shooters worldwide. Whether for varmint control on rural property, small-game hunting, or precision target shooting, the .22 WMR remains a reliable and effective choice that bridges the gap between rimfire simplicity and centerfire performance.