A .22 WMR round will not fit into the chamber of a .22 LR firearm due to the greater length and width of the case dimensions.

Although the bullet diameters are the same, the larger .22 WMR chamber does not support the smaller .22 LR cartridge.

Since the .22 WMR uses bullets comparable in weight to the .22 Long Rifle, but is considerably faster, it shoots flatter and farther and hits harder at all ranges.

The .22 WMR provides improved penetration and more reliable expansion at longer ranges with expanding bullets.

The .22 WMR can effectively kill small game such as rabbits, hares, groundhogs, prairie dogs, foxes, raccoons, opossums, and coyotes.

[citation needed] The relatively quiet report and negligible recoil also make it a very pleasant target and plinking round to shoot for extended periods.

The .22 WMR operates at pressures beyond what normal blowback actions typically handle, but the self-loading Jefferson Model 159 was introduced for the cartridge.

[24] High-Standard produced various models and versions of their classic two-shot over/under derringer in both .22 WMR and .22 LR.

In 2014 Kel-Tec released the CMR-30, a PDW-style rifle chambered in .22 WMR with a 16" barrel and a 1:14 twist rate.

In recent years, a few UK companies such as Guncraft Ltd have been making semi-automatic AR-15-style rifles chambered in 22 WMR, marketed to civilian shooters who, due to the UK's restrictive gun laws, do not have access to self-loading center-fire rifles.

However, Remington, CCI, and Hornady now produce bullet designs with 30 or 33-grain (2.1 g) polymer plastic ballistic tips that reduce the hazards of pointed ammunition in tubular magazines.

Though such bullets are generally heavier than standard .22 WMR, the sharp nose and tapered tail conserve energy better, delivering greater impact at longer ranges.