High Quality Content by WIKIPEDIA articles! The .44 Remington Magnum, or simply .44 Magnum, is a large-bore cartridge originally designed for revolvers. After introduction, it was quickly adopted for carbines and rifles. Despite the ".44" designation, all guns chambered for the .44 Magnum case, and its parent case, the .44 Special, use bullets of approximately 0.429 in (10.9 mm) diameter.