A .22 Magnum (also known as .22 Winchester Magnum Rimfire or .22 WMR) rifle chambered in a semi-automatic action offers a blend of increased ballistic performance compared to the .22 Long Rifle, coupled with the rapid follow-up shots characteristic of a self-loading firearm. These rifles cycle automatically, chambering a new round after each shot without manual operation of the bolt. An example would be a rifle suitable for varmint hunting that allows for quick target acquisition and engagement.
The advantage of such a firearm lies in its capacity for delivering more energy on target at longer ranges than its .22 LR counterpart, enhancing effectiveness against small game and pests. Semi-automatic operation further increases its utility in situations demanding swift follow-up shots. Historically, bolt-action rifles dominated the .22 WMR category. The increasing availability and refinement of semi-automatic platforms have provided an alternative, balancing power and speed.